Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU updates from Paul E. McKenney:

	* Update RCU documentation.  These were posted to LKML at
	  https://lkml.org/lkml/2014/2/17/555.

	* Miscellaneous fixes.  These were posted to LKML at
	  https://lkml.org/lkml/2014/2/17/530.  Note that two of these
	  are RCU changes to other maintainer's trees: add1f09954
	  (fs) and 8857563b81 (notifer), both of which substitute
	  rcu_access_pointer() for rcu_dereference_raw().

	* Real-time latency fixes.  These were posted to LKML at
	  https://lkml.org/lkml/2014/2/17/544.

	* Torture-test changes, including refactoring of rcutorture
	  and introduction of a vestigial locktorture.  These were posted
	  to LKML at https://lkml.org/lkml/2014/2/17/599.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2014-02-28 08:38:30 +01:00
commit 62c206bd51
137 changed files with 2381 additions and 1071 deletions

View File

@ -31,6 +31,14 @@ has lapsed, so this approach may be used in non-GPL software, if desired.
(In contrast, implementation of RCU is permitted only in software licensed
under either GPL or LGPL. Sorry!!!)
In 1987, Rashid et al. described lazy TLB-flush [RichardRashid87a].
At first glance, this has nothing to do with RCU, but nevertheless
this paper helped inspire the update-side batching used in the later
RCU implementation in DYNIX/ptx. In 1988, Barbara Liskov published
a description of Argus that noted that use of out-of-date values can
be tolerated in some situations. Thus, this paper provides some early
theoretical justification for use of stale data.
In 1990, Pugh [Pugh90] noted that explicitly tracking which threads
were reading a given data structure permitted deferred free to operate
in the presence of non-terminating threads. However, this explicit
@ -41,11 +49,11 @@ providing a fine-grained locking design, however, it would be interesting
to see how much of the performance advantage reported in 1990 remains
today.
At about this same time, Adams [Adams91] described ``chaotic relaxation'',
where the normal barriers between successive iterations of convergent
numerical algorithms are relaxed, so that iteration $n$ might use
data from iteration $n-1$ or even $n-2$. This introduces error,
which typically slows convergence and thus increases the number of
At about this same time, Andrews [Andrews91textbook] described ``chaotic
relaxation'', where the normal barriers between successive iterations
of convergent numerical algorithms are relaxed, so that iteration $n$
might use data from iteration $n-1$ or even $n-2$. This introduces
error, which typically slows convergence and thus increases the number of
iterations required. However, this increase is sometimes more than made
up for by a reduction in the number of expensive barrier operations,
which are otherwise required to synchronize the threads at the end
@ -55,7 +63,8 @@ is thus inapplicable to most data structures in operating-system kernels.
In 1992, Henry (now Alexia) Massalin completed a dissertation advising
parallel programmers to defer processing when feasible to simplify
synchronization. RCU makes extremely heavy use of this advice.
synchronization [HMassalinPhD]. RCU makes extremely heavy use of
this advice.
In 1993, Jacobson [Jacobson93] verbally described what is perhaps the
simplest deferred-free technique: simply waiting a fixed amount of time
@ -90,27 +99,29 @@ mechanism, which is quite similar to RCU [Gamsa99]. These operating
systems made pervasive use of RCU in place of "existence locks", which
greatly simplifies locking hierarchies and helps avoid deadlocks.
2001 saw the first RCU presentation involving Linux [McKenney01a]
at OLS. The resulting abundance of RCU patches was presented the
following year [McKenney02a], and use of RCU in dcache was first
described that same year [Linder02a].
The year 2000 saw an email exchange that would likely have
led to yet another independent invention of something like RCU
[RustyRussell2000a,RustyRussell2000b]. Instead, 2001 saw the first
RCU presentation involving Linux [McKenney01a] at OLS. The resulting
abundance of RCU patches was presented the following year [McKenney02a],
and use of RCU in dcache was first described that same year [Linder02a].
Also in 2002, Michael [Michael02b,Michael02a] presented "hazard-pointer"
techniques that defer the destruction of data structures to simplify
non-blocking synchronization (wait-free synchronization, lock-free
synchronization, and obstruction-free synchronization are all examples of
non-blocking synchronization). In particular, this technique eliminates
locking, reduces contention, reduces memory latency for readers, and
parallelizes pipeline stalls and memory latency for writers. However,
these techniques still impose significant read-side overhead in the
form of memory barriers. Researchers at Sun worked along similar lines
in the same timeframe [HerlihyLM02]. These techniques can be thought
of as inside-out reference counts, where the count is represented by the
number of hazard pointers referencing a given data structure rather than
the more conventional counter field within the data structure itself.
The key advantage of inside-out reference counts is that they can be
stored in immortal variables, thus allowing races between access and
deletion to be avoided.
non-blocking synchronization). The corresponding journal article appeared
in 2004 [MagedMichael04a]. This technique eliminates locking, reduces
contention, reduces memory latency for readers, and parallelizes pipeline
stalls and memory latency for writers. However, these techniques still
impose significant read-side overhead in the form of memory barriers.
Researchers at Sun worked along similar lines in the same timeframe
[HerlihyLM02]. These techniques can be thought of as inside-out reference
counts, where the count is represented by the number of hazard pointers
referencing a given data structure rather than the more conventional
counter field within the data structure itself. The key advantage
of inside-out reference counts is that they can be stored in immortal
variables, thus allowing races between access and deletion to be avoided.
By the same token, RCU can be thought of as a "bulk reference count",
where some form of reference counter covers all reference by a given CPU
@ -123,8 +134,10 @@ can be thought of in other terms as well.
In 2003, the K42 group described how RCU could be used to create
hot-pluggable implementations of operating-system functions [Appavoo03a].
Later that year saw a paper describing an RCU implementation of System
V IPC [Arcangeli03], and an introduction to RCU in Linux Journal
Later that year saw a paper describing an RCU implementation
of System V IPC [Arcangeli03] (following up on a suggestion by
Hugh Dickins [Dickins02a] and an implementation by Mingming Cao
[MingmingCao2002IPCRCU]), and an introduction to RCU in Linux Journal
[McKenney03a].
2004 has seen a Linux-Journal article on use of RCU in dcache
@ -383,6 +396,21 @@ for Programming Languages and Operating Systems}"
}
}
@phdthesis{HMassalinPhD
,author="H. Massalin"
,title="Synthesis: An Efficient Implementation of Fundamental Operating
System Services"
,school="Columbia University"
,address="New York, NY"
,year="1992"
,annotation={
Mondo optimizing compiler.
Wait-free stuff.
Good advice: defer work to avoid synchronization. See page 90
(PDF page 106), Section 5.4, fourth bullet point.
}
}
@unpublished{Jacobson93
,author="Van Jacobson"
,title="Avoid Read-Side Locking Via Delayed Free"
@ -671,6 +699,20 @@ Orran Krieger and Rusty Russell and Dipankar Sarma and Maneesh Soni"
[Viewed October 18, 2004]"
}
@conference{Michael02b
,author="Maged M. Michael"
,title="High Performance Dynamic Lock-Free Hash Tables and List-Based Sets"
,Year="2002"
,Month="August"
,booktitle="{Proceedings of the 14\textsuperscript{th} Annual ACM
Symposium on Parallel
Algorithms and Architecture}"
,pages="73-82"
,annotation={
Like the title says...
}
}
@Conference{Linder02a
,Author="Hanna Linder and Dipankar Sarma and Maneesh Soni"
,Title="Scalability of the Directory Entry Cache"
@ -727,6 +769,24 @@ Andrea Arcangeli and Andi Kleen and Orran Krieger and Rusty Russell"
}
}
@conference{Michael02a
,author="Maged M. Michael"
,title="Safe Memory Reclamation for Dynamic Lock-Free Objects Using Atomic
Reads and Writes"
,Year="2002"
,Month="August"
,booktitle="{Proceedings of the 21\textsuperscript{st} Annual ACM
Symposium on Principles of Distributed Computing}"
,pages="21-30"
,annotation={
Each thread keeps an array of pointers to items that it is
currently referencing. Sort of an inside-out garbage collection
mechanism, but one that requires the accessing code to explicitly
state its needs. Also requires read-side memory barriers on
most architectures.
}
}
@unpublished{Dickins02a
,author="Hugh Dickins"
,title="Use RCU for System-V IPC"
@ -735,6 +795,17 @@ Andrea Arcangeli and Andi Kleen and Orran Krieger and Rusty Russell"
,note="private communication"
}
@InProceedings{HerlihyLM02
,author={Maurice Herlihy and Victor Luchangco and Mark Moir}
,title="The Repeat Offender Problem: A Mechanism for Supporting Dynamic-Sized,
Lock-Free Data Structures"
,booktitle={Proceedings of 16\textsuperscript{th} International
Symposium on Distributed Computing}
,year=2002
,month="October"
,pages="339-353"
}
@unpublished{Sarma02b
,Author="Dipankar Sarma"
,Title="Some dcache\_rcu benchmark numbers"
@ -749,6 +820,19 @@ Andrea Arcangeli and Andi Kleen and Orran Krieger and Rusty Russell"
}
}
@unpublished{MingmingCao2002IPCRCU
,Author="Mingming Cao"
,Title="[PATCH]updated ipc lock patch"
,month="October"
,year="2002"
,note="Available:
\url{https://lkml.org/lkml/2002/10/24/262}
[Viewed February 15, 2014]"
,annotation={
Mingming Cao's patch to introduce RCU to SysV IPC.
}
}
@unpublished{LinusTorvalds2003a
,Author="Linus Torvalds"
,Title="Re: {[PATCH]} small fixes in brlock.h"
@ -982,6 +1066,23 @@ Realtime Applications"
}
}
@article{MagedMichael04a
,author="Maged M. Michael"
,title="Hazard Pointers: Safe Memory Reclamation for Lock-Free Objects"
,Year="2004"
,Month="June"
,journal="IEEE Transactions on Parallel and Distributed Systems"
,volume="15"
,number="6"
,pages="491-504"
,url="Available:
\url{http://www.research.ibm.com/people/m/michael/ieeetpds-2004.pdf}
[Viewed March 1, 2005]"
,annotation={
New canonical hazard-pointer citation.
}
}
@phdthesis{PaulEdwardMcKenneyPhD
,author="Paul E. McKenney"
,title="Exploiting Deferred Destruction:

View File

@ -256,10 +256,10 @@ over a rather long period of time, but improvements are always welcome!
variations on this theme.
b. Limiting update rate. For example, if updates occur only
once per hour, then no explicit rate limiting is required,
unless your system is already badly broken. The dcache
subsystem takes this approach -- updates are guarded
by a global lock, limiting their rate.
once per hour, then no explicit rate limiting is
required, unless your system is already badly broken.
Older versions of the dcache subsystem take this approach,
guarding updates with a global lock, limiting their rate.
c. Trusted update -- if updates can only be done manually by
superuser or some other trusted user, then it might not
@ -268,7 +268,8 @@ over a rather long period of time, but improvements are always welcome!
the machine.
d. Use call_rcu_bh() rather than call_rcu(), in order to take
advantage of call_rcu_bh()'s faster grace periods.
advantage of call_rcu_bh()'s faster grace periods. (This
is only a partial solution, though.)
e. Periodically invoke synchronize_rcu(), permitting a limited
number of updates per grace period.
@ -276,6 +277,13 @@ over a rather long period of time, but improvements are always welcome!
The same cautions apply to call_rcu_bh(), call_rcu_sched(),
call_srcu(), and kfree_rcu().
Note that although these primitives do take action to avoid memory
exhaustion when any given CPU has too many callbacks, a determined
user could still exhaust memory. This is especially the case
if a system with a large number of CPUs has been configured to
offload all of its RCU callbacks onto a single CPU, or if the
system has relatively little free memory.
9. All RCU list-traversal primitives, which include
rcu_dereference(), list_for_each_entry_rcu(), and
list_for_each_safe_rcu(), must be either within an RCU read-side

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@ -162,7 +162,18 @@ Purpose: Execute workqueue requests
To reduce its OS jitter, do any of the following:
1. Run your workload at a real-time priority, which will allow
preempting the kworker daemons.
2. Do any of the following needed to avoid jitter that your
2. A given workqueue can be made visible in the sysfs filesystem
by passing the WQ_SYSFS to that workqueue's alloc_workqueue().
Such a workqueue can be confined to a given subset of the
CPUs using the /sys/devices/virtual/workqueue/*/cpumask sysfs
files. The set of WQ_SYSFS workqueues can be displayed using
"ls sys/devices/virtual/workqueue". That said, the workqueues
maintainer would like to caution people against indiscriminately
sprinkling WQ_SYSFS across all the workqueues. The reason for
caution is that it is easy to add WQ_SYSFS, but because sysfs is
part of the formal user/kernel API, it can be nearly impossible
to remove it, even if its addition was a mistake.
3. Do any of the following needed to avoid jitter that your
application cannot tolerate:
a. Build your kernel with CONFIG_SLUB=y rather than
CONFIG_SLAB=y, thus avoiding the slab allocator's periodic

View File

@ -608,26 +608,30 @@ as follows:
b = p; /* BUG: Compiler can reorder!!! */
do_something();
The solution is again ACCESS_ONCE(), which preserves the ordering between
the load from variable 'a' and the store to variable 'b':
The solution is again ACCESS_ONCE() and barrier(), which preserves the
ordering between the load from variable 'a' and the store to variable 'b':
q = ACCESS_ONCE(a);
if (q) {
barrier();
ACCESS_ONCE(b) = p;
do_something();
} else {
barrier();
ACCESS_ONCE(b) = p;
do_something_else();
}
You could also use barrier() to prevent the compiler from moving
the stores to variable 'b', but barrier() would not prevent the
compiler from proving to itself that a==1 always, so ACCESS_ONCE()
is also needed.
The initial ACCESS_ONCE() is required to prevent the compiler from
proving the value of 'a', and the pair of barrier() invocations are
required to prevent the compiler from pulling the two identical stores
to 'b' out from the legs of the "if" statement.
It is important to note that control dependencies absolutely require a
a conditional. For example, the following "optimized" version of
the above example breaks ordering:
the above example breaks ordering, which is why the barrier() invocations
are absolutely required if you have identical stores in both legs of
the "if" statement:
q = ACCESS_ONCE(a);
ACCESS_ONCE(b) = p; /* BUG: No ordering vs. load from a!!! */
@ -643,9 +647,11 @@ It is of course legal for the prior load to be part of the conditional,
for example, as follows:
if (ACCESS_ONCE(a) > 0) {
barrier();
ACCESS_ONCE(b) = q / 2;
do_something();
} else {
barrier();
ACCESS_ONCE(b) = q / 3;
do_something_else();
}
@ -659,9 +665,11 @@ the needed conditional. For example:
q = ACCESS_ONCE(a);
if (q % MAX) {
barrier();
ACCESS_ONCE(b) = p;
do_something();
} else {
barrier();
ACCESS_ONCE(b) = p;
do_something_else();
}
@ -723,8 +731,13 @@ In summary:
use smb_rmb(), smp_wmb(), or, in the case of prior stores and
later loads, smp_mb().
(*) If both legs of the "if" statement begin with identical stores
to the same variable, a barrier() statement is required at the
beginning of each leg of the "if" statement.
(*) Control dependencies require at least one run-time conditional
between the prior load and the subsequent store. If the compiler
between the prior load and the subsequent store, and this
conditional must involve the prior load. If the compiler
is able to optimize the conditional away, it will have also
optimized away the ordering. Careful use of ACCESS_ONCE() can
help to preserve the needed conditional.
@ -1249,6 +1262,23 @@ The ACCESS_ONCE() function can prevent any number of optimizations that,
while perfectly safe in single-threaded code, can be fatal in concurrent
code. Here are some examples of these sorts of optimizations:
(*) The compiler is within its rights to reorder loads and stores
to the same variable, and in some cases, the CPU is within its
rights to reorder loads to the same variable. This means that
the following code:
a[0] = x;
a[1] = x;
Might result in an older value of x stored in a[1] than in a[0].
Prevent both the compiler and the CPU from doing this as follows:
a[0] = ACCESS_ONCE(x);
a[1] = ACCESS_ONCE(x);
In short, ACCESS_ONCE() provides cache coherence for accesses from
multiple CPUs to a single variable.
(*) The compiler is within its rights to merge successive loads from
the same variable. Such merging can cause the compiler to "optimize"
the following code:
@ -1644,12 +1674,12 @@ for each construct. These operations all imply certain barriers:
Memory operations issued after the ACQUIRE will be completed after the
ACQUIRE operation has completed.
Memory operations issued before the ACQUIRE may be completed after the
ACQUIRE operation has completed. An smp_mb__before_spinlock(), combined
with a following ACQUIRE, orders prior loads against subsequent stores and
stores and prior stores against subsequent stores. Note that this is
weaker than smp_mb()! The smp_mb__before_spinlock() primitive is free on
many architectures.
Memory operations issued before the ACQUIRE may be completed after
the ACQUIRE operation has completed. An smp_mb__before_spinlock(),
combined with a following ACQUIRE, orders prior loads against
subsequent loads and stores and also orders prior stores against
subsequent stores. Note that this is weaker than smp_mb()! The
smp_mb__before_spinlock() primitive is free on many architectures.
(2) RELEASE operation implication:
@ -1694,24 +1724,21 @@ may occur as:
ACQUIRE M, STORE *B, STORE *A, RELEASE M
This same reordering can of course occur if the lock's ACQUIRE and RELEASE are
to the same lock variable, but only from the perspective of another CPU not
holding that lock.
When the ACQUIRE and RELEASE are a lock acquisition and release,
respectively, this same reordering can occur if the lock's ACQUIRE and
RELEASE are to the same lock variable, but only from the perspective of
another CPU not holding that lock. In short, a ACQUIRE followed by an
RELEASE may -not- be assumed to be a full memory barrier.
In short, a RELEASE followed by an ACQUIRE may -not- be assumed to be a full
memory barrier because it is possible for a preceding RELEASE to pass a
later ACQUIRE from the viewpoint of the CPU, but not from the viewpoint
of the compiler. Note that deadlocks cannot be introduced by this
interchange because if such a deadlock threatened, the RELEASE would
simply complete.
If it is necessary for a RELEASE-ACQUIRE pair to produce a full barrier, the
ACQUIRE can be followed by an smp_mb__after_unlock_lock() invocation. This
will produce a full barrier if either (a) the RELEASE and the ACQUIRE are
executed by the same CPU or task, or (b) the RELEASE and ACQUIRE act on the
same variable. The smp_mb__after_unlock_lock() primitive is free on many
architectures. Without smp_mb__after_unlock_lock(), the critical sections
corresponding to the RELEASE and the ACQUIRE can cross:
Similarly, the reverse case of a RELEASE followed by an ACQUIRE does not
imply a full memory barrier. If it is necessary for a RELEASE-ACQUIRE
pair to produce a full barrier, the ACQUIRE can be followed by an
smp_mb__after_unlock_lock() invocation. This will produce a full barrier
if either (a) the RELEASE and the ACQUIRE are executed by the same
CPU or task, or (b) the RELEASE and ACQUIRE act on the same variable.
The smp_mb__after_unlock_lock() primitive is free on many architectures.
Without smp_mb__after_unlock_lock(), the CPU's execution of the critical
sections corresponding to the RELEASE and the ACQUIRE can cross, so that:
*A = a;
RELEASE M
@ -1722,7 +1749,36 @@ could occur as:
ACQUIRE N, STORE *B, STORE *A, RELEASE M
With smp_mb__after_unlock_lock(), they cannot, so that:
It might appear that this reordering could introduce a deadlock.
However, this cannot happen because if such a deadlock threatened,
the RELEASE would simply complete, thereby avoiding the deadlock.
Why does this work?
One key point is that we are only talking about the CPU doing
the reordering, not the compiler. If the compiler (or, for
that matter, the developer) switched the operations, deadlock
-could- occur.
But suppose the CPU reordered the operations. In this case,
the unlock precedes the lock in the assembly code. The CPU
simply elected to try executing the later lock operation first.
If there is a deadlock, this lock operation will simply spin (or
try to sleep, but more on that later). The CPU will eventually
execute the unlock operation (which preceded the lock operation
in the assembly code), which will unravel the potential deadlock,
allowing the lock operation to succeed.
But what if the lock is a sleeplock? In that case, the code will
try to enter the scheduler, where it will eventually encounter
a memory barrier, which will force the earlier unlock operation
to complete, again unraveling the deadlock. There might be
a sleep-unlock race, but the locking primitive needs to resolve
such races properly in any case.
With smp_mb__after_unlock_lock(), the two critical sections cannot overlap.
For example, with the following code, the store to *A will always be
seen by other CPUs before the store to *B:
*A = a;
RELEASE M
@ -1730,13 +1786,18 @@ With smp_mb__after_unlock_lock(), they cannot, so that:
smp_mb__after_unlock_lock();
*B = b;
will always occur as either of the following:
The operations will always occur in one of the following orders:
STORE *A, RELEASE, ACQUIRE, STORE *B
STORE *A, ACQUIRE, RELEASE, STORE *B
STORE *A, RELEASE, ACQUIRE, smp_mb__after_unlock_lock(), STORE *B
STORE *A, ACQUIRE, RELEASE, smp_mb__after_unlock_lock(), STORE *B
ACQUIRE, STORE *A, RELEASE, smp_mb__after_unlock_lock(), STORE *B
If the RELEASE and ACQUIRE were instead both operating on the same lock
variable, only the first of these two alternatives can occur.
variable, only the first of these alternatives can occur. In addition,
the more strongly ordered systems may rule out some of the above orders.
But in any case, as noted earlier, the smp_mb__after_unlock_lock()
ensures that the store to *A will always be seen as happening before
the store to *B.
Locks and semaphores may not provide any guarantee of ordering on UP compiled
systems, and so cannot be counted on in such a situation to actually achieve
@ -2757,7 +2818,7 @@ in that order, but, without intervention, the sequence may have almost any
combination of elements combined or discarded, provided the program's view of
the world remains consistent. Note that ACCESS_ONCE() is -not- optional
in the above example, as there are architectures where a given CPU might
interchange successive loads to the same location. On such architectures,
reorder successive loads to the same location. On such architectures,
ACCESS_ONCE() does whatever is necessary to prevent this, for example, on
Itanium the volatile casts used by ACCESS_ONCE() cause GCC to emit the
special ld.acq and st.rel instructions that prevent such reordering.

View File

@ -497,7 +497,7 @@ repeat:
error = fd;
#if 1
/* Sanity check */
if (rcu_dereference_raw(fdt->fd[fd]) != NULL) {
if (rcu_access_pointer(fdt->fd[fd]) != NULL) {
printk(KERN_WARNING "alloc_fd: slot %d not NULL!\n", fd);
rcu_assign_pointer(fdt->fd[fd], NULL);
}

View File

@ -247,9 +247,10 @@ static inline void list_splice_init_rcu(struct list_head *list,
* primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
*/
#define list_entry_rcu(ptr, type, member) \
({typeof (*ptr) __rcu *__ptr = (typeof (*ptr) __rcu __force *)ptr; \
container_of((typeof(ptr))rcu_dereference_raw(__ptr), type, member); \
})
({ \
typeof(*ptr) __rcu *__ptr = (typeof(*ptr) __rcu __force *)ptr; \
container_of((typeof(ptr))rcu_dereference_raw(__ptr), type, member); \
})
/**
* Where are list_empty_rcu() and list_first_entry_rcu()?
@ -285,11 +286,11 @@ static inline void list_splice_init_rcu(struct list_head *list,
* primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
*/
#define list_first_or_null_rcu(ptr, type, member) \
({struct list_head *__ptr = (ptr); \
struct list_head *__next = ACCESS_ONCE(__ptr->next); \
likely(__ptr != __next) ? \
list_entry_rcu(__next, type, member) : NULL; \
})
({ \
struct list_head *__ptr = (ptr); \
struct list_head *__next = ACCESS_ONCE(__ptr->next); \
likely(__ptr != __next) ? list_entry_rcu(__next, type, member) : NULL; \
})
/**
* list_for_each_entry_rcu - iterate over rcu list of given type

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2001
*
@ -44,7 +44,9 @@
#include <linux/debugobjects.h>
#include <linux/bug.h>
#include <linux/compiler.h>
#include <asm/barrier.h>
extern int rcu_expedited; /* for sysctl */
#ifdef CONFIG_RCU_TORTURE_TEST
extern int rcutorture_runnable; /* for sysctl */
#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
@ -479,11 +481,9 @@ static inline void rcu_preempt_sleep_check(void)
do { \
rcu_preempt_sleep_check(); \
rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map), \
"Illegal context switch in RCU-bh" \
" read-side critical section"); \
"Illegal context switch in RCU-bh read-side critical section"); \
rcu_lockdep_assert(!lock_is_held(&rcu_sched_lock_map), \
"Illegal context switch in RCU-sched"\
" read-side critical section"); \
"Illegal context switch in RCU-sched read-side critical section"); \
} while (0)
#else /* #ifdef CONFIG_PROVE_RCU */
@ -510,43 +510,40 @@ static inline void rcu_preempt_sleep_check(void)
#endif /* #else #ifdef __CHECKER__ */
#define __rcu_access_pointer(p, space) \
({ \
typeof(*p) *_________p1 = (typeof(*p)*__force )ACCESS_ONCE(p); \
rcu_dereference_sparse(p, space); \
((typeof(*p) __force __kernel *)(_________p1)); \
})
({ \
typeof(*p) *_________p1 = (typeof(*p) *__force)ACCESS_ONCE(p); \
rcu_dereference_sparse(p, space); \
((typeof(*p) __force __kernel *)(_________p1)); \
})
#define __rcu_dereference_check(p, c, space) \
({ \
typeof(*p) *_________p1 = (typeof(*p)*__force )ACCESS_ONCE(p); \
rcu_lockdep_assert(c, "suspicious rcu_dereference_check()" \
" usage"); \
rcu_dereference_sparse(p, space); \
smp_read_barrier_depends(); \
((typeof(*p) __force __kernel *)(_________p1)); \
})
({ \
typeof(*p) *_________p1 = (typeof(*p) *__force)ACCESS_ONCE(p); \
rcu_lockdep_assert(c, "suspicious rcu_dereference_check() usage"); \
rcu_dereference_sparse(p, space); \
smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
((typeof(*p) __force __kernel *)(_________p1)); \
})
#define __rcu_dereference_protected(p, c, space) \
({ \
rcu_lockdep_assert(c, "suspicious rcu_dereference_protected()" \
" usage"); \
rcu_dereference_sparse(p, space); \
((typeof(*p) __force __kernel *)(p)); \
})
({ \
rcu_lockdep_assert(c, "suspicious rcu_dereference_protected() usage"); \
rcu_dereference_sparse(p, space); \
((typeof(*p) __force __kernel *)(p)); \
})
#define __rcu_access_index(p, space) \
({ \
typeof(p) _________p1 = ACCESS_ONCE(p); \
rcu_dereference_sparse(p, space); \
(_________p1); \
})
({ \
typeof(p) _________p1 = ACCESS_ONCE(p); \
rcu_dereference_sparse(p, space); \
(_________p1); \
})
#define __rcu_dereference_index_check(p, c) \
({ \
typeof(p) _________p1 = ACCESS_ONCE(p); \
rcu_lockdep_assert(c, \
"suspicious rcu_dereference_index_check()" \
" usage"); \
smp_read_barrier_depends(); \
(_________p1); \
})
({ \
typeof(p) _________p1 = ACCESS_ONCE(p); \
rcu_lockdep_assert(c, \
"suspicious rcu_dereference_index_check() usage"); \
smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
(_________p1); \
})
/**
* RCU_INITIALIZER() - statically initialize an RCU-protected global variable
@ -585,12 +582,7 @@ static inline void rcu_preempt_sleep_check(void)
* please be careful when making changes to rcu_assign_pointer() and the
* other macros that it invokes.
*/
#define rcu_assign_pointer(p, v) \
do { \
smp_wmb(); \
ACCESS_ONCE(p) = RCU_INITIALIZER(v); \
} while (0)
#define rcu_assign_pointer(p, v) smp_store_release(&p, RCU_INITIALIZER(v))
/**
* rcu_access_pointer() - fetch RCU pointer with no dereferencing
@ -1015,11 +1007,21 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
#define kfree_rcu(ptr, rcu_head) \
__kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head))
#ifdef CONFIG_RCU_NOCB_CPU
#if defined(CONFIG_TINY_RCU) || defined(CONFIG_RCU_NOCB_CPU_ALL)
static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
{
*delta_jiffies = ULONG_MAX;
return 0;
}
#endif /* #if defined(CONFIG_TINY_RCU) || defined(CONFIG_RCU_NOCB_CPU_ALL) */
#if defined(CONFIG_RCU_NOCB_CPU_ALL)
static inline bool rcu_is_nocb_cpu(int cpu) { return true; }
#elif defined(CONFIG_RCU_NOCB_CPU)
bool rcu_is_nocb_cpu(int cpu);
#else
static inline bool rcu_is_nocb_cpu(int cpu) { return false; }
#endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */
#endif
/* Only for use by adaptive-ticks code. */

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2008
*
@ -68,12 +68,6 @@ static inline void kfree_call_rcu(struct rcu_head *head,
call_rcu(head, func);
}
static inline int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
{
*delta_jiffies = ULONG_MAX;
return 0;
}
static inline void rcu_note_context_switch(int cpu)
{
rcu_sched_qs(cpu);

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2008
*
@ -31,7 +31,9 @@
#define __LINUX_RCUTREE_H
void rcu_note_context_switch(int cpu);
#ifndef CONFIG_RCU_NOCB_CPU_ALL
int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies);
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
void rcu_cpu_stall_reset(void);
/*

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright (C) IBM Corporation, 2006
* Copyright (C) Fujitsu, 2012

100
include/linux/torture.h Normal file
View File

@ -0,0 +1,100 @@
/*
* Common functions for in-kernel torture tests.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2014
*
* Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
*/
#ifndef __LINUX_TORTURE_H
#define __LINUX_TORTURE_H
#include <linux/types.h>
#include <linux/cache.h>
#include <linux/spinlock.h>
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/seqlock.h>
#include <linux/lockdep.h>
#include <linux/completion.h>
#include <linux/debugobjects.h>
#include <linux/bug.h>
#include <linux/compiler.h>
/* Definitions for a non-string torture-test module parameter. */
#define torture_param(type, name, init, msg) \
static type name = init; \
module_param(name, type, 0444); \
MODULE_PARM_DESC(name, msg);
#define TORTURE_FLAG "-torture:"
#define TOROUT_STRING(s) \
pr_alert("%s" TORTURE_FLAG s "\n", torture_type)
#define VERBOSE_TOROUT_STRING(s) \
do { if (verbose) pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s); } while (0)
#define VERBOSE_TOROUT_ERRSTRING(s) \
do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); } while (0)
/* Definitions for a non-string torture-test module parameter. */
#define torture_parm(type, name, init, msg) \
static type name = init; \
module_param(name, type, 0444); \
MODULE_PARM_DESC(name, msg);
/* Definitions for online/offline exerciser. */
int torture_onoff_init(long ooholdoff, long oointerval);
char *torture_onoff_stats(char *page);
bool torture_onoff_failures(void);
/* Low-rider random number generator. */
struct torture_random_state {
unsigned long trs_state;
long trs_count;
};
#define DEFINE_TORTURE_RANDOM(name) struct torture_random_state name = { 0, 0 }
unsigned long torture_random(struct torture_random_state *trsp);
/* Task shuffler, which causes CPUs to occasionally go idle. */
void torture_shuffle_task_register(struct task_struct *tp);
int torture_shuffle_init(long shuffint);
/* Test auto-shutdown handling. */
void torture_shutdown_absorb(const char *title);
int torture_shutdown_init(int ssecs, void (*cleanup)(void));
/* Task stuttering, which forces load/no-load transitions. */
void stutter_wait(const char *title);
int torture_stutter_init(int s);
/* Initialization and cleanup. */
void torture_init_begin(char *ttype, bool v, int *runnable);
void torture_init_end(void);
bool torture_cleanup(void);
bool torture_must_stop(void);
bool torture_must_stop_irq(void);
void torture_kthread_stopping(char *title);
int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
char *f, struct task_struct **tp);
void _torture_stop_kthread(char *m, struct task_struct **tp);
#define torture_create_kthread(n, arg, tp) \
_torture_create_kthread(n, (arg), #n, "Creating " #n " task", \
"Failed to create " #n, &(tp))
#define torture_stop_kthread(n, tp) \
_torture_stop_kthread("Stopping " #n " task", &(tp))
#endif /* __LINUX_TORTURE_H */

View File

@ -93,6 +93,7 @@ obj-$(CONFIG_PADATA) += padata.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o
obj-$(CONFIG_TORTURE_TEST) += torture.o
$(obj)/configs.o: $(obj)/config_data.h

View File

@ -19,6 +19,8 @@
#include <linux/sched.h>
#include <linux/capability.h>
#include <linux/rcupdate.h> /* rcu_expedited */
#define KERNEL_ATTR_RO(_name) \
static struct kobj_attribute _name##_attr = __ATTR_RO(_name)

View File

@ -23,3 +23,4 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o
obj-$(CONFIG_PERCPU_RWSEM) += percpu-rwsem.o
obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o

View File

@ -0,0 +1,452 @@
/*
* Module-based torture test facility for locking
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright (C) IBM Corporation, 2014
*
* Author: Paul E. McKenney <paulmck@us.ibm.com>
* Based on kernel/rcu/torture.c.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/moduleparam.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/freezer.h>
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/trace_clock.h>
#include <asm/byteorder.h>
#include <linux/torture.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
torture_param(int, nwriters_stress, -1,
"Number of write-locking stress-test threads");
torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
torture_param(int, onoff_interval, 0,
"Time between CPU hotplugs (s), 0=disable");
torture_param(int, shuffle_interval, 3,
"Number of jiffies between shuffles, 0=disable");
torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
torture_param(int, stat_interval, 60,
"Number of seconds between stats printk()s");
torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
torture_param(bool, verbose, true,
"Enable verbose debugging printk()s");
static char *torture_type = "spin_lock";
module_param(torture_type, charp, 0444);
MODULE_PARM_DESC(torture_type,
"Type of lock to torture (spin_lock, spin_lock_irq, ...)");
static atomic_t n_lock_torture_errors;
static struct task_struct *stats_task;
static struct task_struct **writer_tasks;
static int nrealwriters_stress;
static bool lock_is_write_held;
struct lock_writer_stress_stats {
long n_write_lock_fail;
long n_write_lock_acquired;
};
static struct lock_writer_stress_stats *lwsa;
#if defined(MODULE) || defined(CONFIG_LOCK_TORTURE_TEST_RUNNABLE)
#define LOCKTORTURE_RUNNABLE_INIT 1
#else
#define LOCKTORTURE_RUNNABLE_INIT 0
#endif
int locktorture_runnable = LOCKTORTURE_RUNNABLE_INIT;
module_param(locktorture_runnable, int, 0444);
MODULE_PARM_DESC(locktorture_runnable, "Start locktorture at boot");
/* Forward reference. */
static void lock_torture_cleanup(void);
/*
* Operations vector for selecting different types of tests.
*/
struct lock_torture_ops {
void (*init)(void);
int (*writelock)(void);
void (*write_delay)(struct torture_random_state *trsp);
void (*writeunlock)(void);
unsigned long flags;
const char *name;
};
static struct lock_torture_ops *cur_ops;
/*
* Definitions for lock torture testing.
*/
static int torture_lock_busted_write_lock(void)
{
return 0; /* BUGGY, do not use in real life!!! */
}
static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
{
const unsigned long longdelay_us = 100;
/* We want a long delay occasionally to force massive contention. */
if (!(torture_random(trsp) %
(nrealwriters_stress * 2000 * longdelay_us)))
mdelay(longdelay_us);
#ifdef CONFIG_PREEMPT
if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
preempt_schedule(); /* Allow test to be preempted. */
#endif
}
static void torture_lock_busted_write_unlock(void)
{
/* BUGGY, do not use in real life!!! */
}
static struct lock_torture_ops lock_busted_ops = {
.writelock = torture_lock_busted_write_lock,
.write_delay = torture_lock_busted_write_delay,
.writeunlock = torture_lock_busted_write_unlock,
.name = "lock_busted"
};
static DEFINE_SPINLOCK(torture_spinlock);
static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
{
spin_lock(&torture_spinlock);
return 0;
}
static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
{
const unsigned long shortdelay_us = 2;
const unsigned long longdelay_us = 100;
/* We want a short delay mostly to emulate likely code, and
* we want a long delay occasionally to force massive contention.
*/
if (!(torture_random(trsp) %
(nrealwriters_stress * 2000 * longdelay_us)))
mdelay(longdelay_us);
if (!(torture_random(trsp) %
(nrealwriters_stress * 2 * shortdelay_us)))
udelay(shortdelay_us);
#ifdef CONFIG_PREEMPT
if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
preempt_schedule(); /* Allow test to be preempted. */
#endif
}
static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
{
spin_unlock(&torture_spinlock);
}
static struct lock_torture_ops spin_lock_ops = {
.writelock = torture_spin_lock_write_lock,
.write_delay = torture_spin_lock_write_delay,
.writeunlock = torture_spin_lock_write_unlock,
.name = "spin_lock"
};
static int torture_spin_lock_write_lock_irq(void)
__acquires(torture_spinlock_irq)
{
unsigned long flags;
spin_lock_irqsave(&torture_spinlock, flags);
cur_ops->flags = flags;
return 0;
}
static void torture_lock_spin_write_unlock_irq(void)
__releases(torture_spinlock)
{
spin_unlock_irqrestore(&torture_spinlock, cur_ops->flags);
}
static struct lock_torture_ops spin_lock_irq_ops = {
.writelock = torture_spin_lock_write_lock_irq,
.write_delay = torture_spin_lock_write_delay,
.writeunlock = torture_lock_spin_write_unlock_irq,
.name = "spin_lock_irq"
};
/*
* Lock torture writer kthread. Repeatedly acquires and releases
* the lock, checking for duplicate acquisitions.
*/
static int lock_torture_writer(void *arg)
{
struct lock_writer_stress_stats *lwsp = arg;
static DEFINE_TORTURE_RANDOM(rand);
VERBOSE_TOROUT_STRING("lock_torture_writer task started");
set_user_nice(current, 19);
do {
schedule_timeout_uninterruptible(1);
cur_ops->writelock();
if (WARN_ON_ONCE(lock_is_write_held))
lwsp->n_write_lock_fail++;
lock_is_write_held = 1;
lwsp->n_write_lock_acquired++;
cur_ops->write_delay(&rand);
lock_is_write_held = 0;
cur_ops->writeunlock();
stutter_wait("lock_torture_writer");
} while (!torture_must_stop());
torture_kthread_stopping("lock_torture_writer");
return 0;
}
/*
* Create an lock-torture-statistics message in the specified buffer.
*/
static void lock_torture_printk(char *page)
{
bool fail = 0;
int i;
long max = 0;
long min = lwsa[0].n_write_lock_acquired;
long long sum = 0;
for (i = 0; i < nrealwriters_stress; i++) {
if (lwsa[i].n_write_lock_fail)
fail = true;
sum += lwsa[i].n_write_lock_acquired;
if (max < lwsa[i].n_write_lock_fail)
max = lwsa[i].n_write_lock_fail;
if (min > lwsa[i].n_write_lock_fail)
min = lwsa[i].n_write_lock_fail;
}
page += sprintf(page, "%s%s ", torture_type, TORTURE_FLAG);
page += sprintf(page,
"Writes: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n",
sum, max, min, max / 2 > min ? "???" : "",
fail, fail ? "!!!" : "");
if (fail)
atomic_inc(&n_lock_torture_errors);
}
/*
* Print torture statistics. Caller must ensure that there is only one
* call to this function at a given time!!! This is normally accomplished
* by relying on the module system to only have one copy of the module
* loaded, and then by giving the lock_torture_stats kthread full control
* (or the init/cleanup functions when lock_torture_stats thread is not
* running).
*/
static void lock_torture_stats_print(void)
{
int size = nrealwriters_stress * 200 + 8192;
char *buf;
buf = kmalloc(size, GFP_KERNEL);
if (!buf) {
pr_err("lock_torture_stats_print: Out of memory, need: %d",
size);
return;
}
lock_torture_printk(buf);
pr_alert("%s", buf);
kfree(buf);
}
/*
* Periodically prints torture statistics, if periodic statistics printing
* was specified via the stat_interval module parameter.
*
* No need to worry about fullstop here, since this one doesn't reference
* volatile state or register callbacks.
*/
static int lock_torture_stats(void *arg)
{
VERBOSE_TOROUT_STRING("lock_torture_stats task started");
do {
schedule_timeout_interruptible(stat_interval * HZ);
lock_torture_stats_print();
torture_shutdown_absorb("lock_torture_stats");
} while (!torture_must_stop());
torture_kthread_stopping("lock_torture_stats");
return 0;
}
static inline void
lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
const char *tag)
{
pr_alert("%s" TORTURE_FLAG
"--- %s: nwriters_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
torture_type, tag, nrealwriters_stress, stat_interval, verbose,
shuffle_interval, stutter, shutdown_secs,
onoff_interval, onoff_holdoff);
}
static void lock_torture_cleanup(void)
{
int i;
if (torture_cleanup())
return;
if (writer_tasks) {
for (i = 0; i < nrealwriters_stress; i++)
torture_stop_kthread(lock_torture_writer,
writer_tasks[i]);
kfree(writer_tasks);
writer_tasks = NULL;
}
torture_stop_kthread(lock_torture_stats, stats_task);
lock_torture_stats_print(); /* -After- the stats thread is stopped! */
if (atomic_read(&n_lock_torture_errors))
lock_torture_print_module_parms(cur_ops,
"End of test: FAILURE");
else if (torture_onoff_failures())
lock_torture_print_module_parms(cur_ops,
"End of test: LOCK_HOTPLUG");
else
lock_torture_print_module_parms(cur_ops,
"End of test: SUCCESS");
}
static int __init lock_torture_init(void)
{
int i;
int firsterr = 0;
static struct lock_torture_ops *torture_ops[] = {
&lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops,
};
torture_init_begin(torture_type, verbose, &locktorture_runnable);
/* Process args and tell the world that the torturer is on the job. */
for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
cur_ops = torture_ops[i];
if (strcmp(torture_type, cur_ops->name) == 0)
break;
}
if (i == ARRAY_SIZE(torture_ops)) {
pr_alert("lock-torture: invalid torture type: \"%s\"\n",
torture_type);
pr_alert("lock-torture types:");
for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
pr_alert(" %s", torture_ops[i]->name);
pr_alert("\n");
torture_init_end();
return -EINVAL;
}
if (cur_ops->init)
cur_ops->init(); /* no "goto unwind" prior to this point!!! */
if (nwriters_stress >= 0)
nrealwriters_stress = nwriters_stress;
else
nrealwriters_stress = 2 * num_online_cpus();
lock_torture_print_module_parms(cur_ops, "Start of test");
/* Initialize the statistics so that each run gets its own numbers. */
lock_is_write_held = 0;
lwsa = kmalloc(sizeof(*lwsa) * nrealwriters_stress, GFP_KERNEL);
if (lwsa == NULL) {
VERBOSE_TOROUT_STRING("lwsa: Out of memory");
firsterr = -ENOMEM;
goto unwind;
}
for (i = 0; i < nrealwriters_stress; i++) {
lwsa[i].n_write_lock_fail = 0;
lwsa[i].n_write_lock_acquired = 0;
}
/* Start up the kthreads. */
if (onoff_interval > 0) {
firsterr = torture_onoff_init(onoff_holdoff * HZ,
onoff_interval * HZ);
if (firsterr)
goto unwind;
}
if (shuffle_interval > 0) {
firsterr = torture_shuffle_init(shuffle_interval);
if (firsterr)
goto unwind;
}
if (shutdown_secs > 0) {
firsterr = torture_shutdown_init(shutdown_secs,
lock_torture_cleanup);
if (firsterr)
goto unwind;
}
if (stutter > 0) {
firsterr = torture_stutter_init(stutter);
if (firsterr)
goto unwind;
}
writer_tasks = kzalloc(nrealwriters_stress * sizeof(writer_tasks[0]),
GFP_KERNEL);
if (writer_tasks == NULL) {
VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
firsterr = -ENOMEM;
goto unwind;
}
for (i = 0; i < nrealwriters_stress; i++) {
firsterr = torture_create_kthread(lock_torture_writer, &lwsa[i],
writer_tasks[i]);
if (firsterr)
goto unwind;
}
if (stat_interval > 0) {
firsterr = torture_create_kthread(lock_torture_stats, NULL,
stats_task);
if (firsterr)
goto unwind;
}
torture_init_end();
return 0;
unwind:
torture_init_end();
lock_torture_cleanup();
return firsterr;
}
module_init(lock_torture_init);
module_exit(lock_torture_cleanup);

View File

@ -309,7 +309,7 @@ int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
* racy then it does not matter what the result of the test
* is, we re-check the list after having taken the lock anyway:
*/
if (rcu_dereference_raw(nh->head)) {
if (rcu_access_pointer(nh->head)) {
down_read(&nh->rwsem);
ret = notifier_call_chain(&nh->head, val, v, nr_to_call,
nr_calls);

View File

@ -1,5 +1,5 @@
obj-y += update.o srcu.o
obj-$(CONFIG_RCU_TORTURE_TEST) += torture.o
obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
obj-$(CONFIG_TREE_RCU) += tree.o
obj-$(CONFIG_TREE_PREEMPT_RCU) += tree.o
obj-$(CONFIG_TREE_RCU_TRACE) += tree_trace.o

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2011
*
@ -23,6 +23,7 @@
#ifndef __LINUX_RCU_H
#define __LINUX_RCU_H
#include <trace/events/rcu.h>
#ifdef CONFIG_RCU_TRACE
#define RCU_TRACE(stmt) stmt
#else /* #ifdef CONFIG_RCU_TRACE */
@ -116,8 +117,6 @@ static inline bool __rcu_reclaim(const char *rn, struct rcu_head *head)
}
}
extern int rcu_expedited;
#ifdef CONFIG_RCU_STALL_COMMON
extern int rcu_cpu_stall_suppress;

File diff suppressed because it is too large Load Diff

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright (C) IBM Corporation, 2006
* Copyright (C) Fujitsu, 2012
@ -36,8 +36,6 @@
#include <linux/delay.h>
#include <linux/srcu.h>
#include <trace/events/rcu.h>
#include "rcu.h"
/*
@ -398,7 +396,7 @@ void call_srcu(struct srcu_struct *sp, struct rcu_head *head,
rcu_batch_queue(&sp->batch_queue, head);
if (!sp->running) {
sp->running = true;
schedule_delayed_work(&sp->work, 0);
queue_delayed_work(system_power_efficient_wq, &sp->work, 0);
}
spin_unlock_irqrestore(&sp->queue_lock, flags);
}
@ -674,7 +672,8 @@ static void srcu_reschedule(struct srcu_struct *sp)
}
if (pending)
schedule_delayed_work(&sp->work, SRCU_INTERVAL);
queue_delayed_work(system_power_efficient_wq,
&sp->work, SRCU_INTERVAL);
}
/*

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2008
*
@ -37,10 +37,6 @@
#include <linux/prefetch.h>
#include <linux/ftrace_event.h>
#ifdef CONFIG_RCU_TRACE
#include <trace/events/rcu.h>
#endif /* #else #ifdef CONFIG_RCU_TRACE */
#include "rcu.h"
/* Forward declarations for tiny_plugin.h. */

View File

@ -14,8 +14,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright (c) 2010 Linaro
*

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2008
*
@ -58,8 +58,6 @@
#include <linux/suspend.h>
#include "tree.h"
#include <trace/events/rcu.h>
#include "rcu.h"
MODULE_ALIAS("rcutree");
@ -837,7 +835,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
* to the next. Only do this for the primary flavor of RCU.
*/
if (rdp->rsp == rcu_state &&
ULONG_CMP_GE(ACCESS_ONCE(jiffies), rdp->rsp->jiffies_resched)) {
ULONG_CMP_GE(jiffies, rdp->rsp->jiffies_resched)) {
rdp->rsp->jiffies_resched += 5;
resched_cpu(rdp->cpu);
}
@ -847,7 +845,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
static void record_gp_stall_check_time(struct rcu_state *rsp)
{
unsigned long j = ACCESS_ONCE(jiffies);
unsigned long j = jiffies;
unsigned long j1;
rsp->gp_start = j;
@ -1005,7 +1003,7 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
if (rcu_cpu_stall_suppress || !rcu_gp_in_progress(rsp))
return;
j = ACCESS_ONCE(jiffies);
j = jiffies;
/*
* Lots of memory barriers to reject false positives.
@ -2304,7 +2302,7 @@ static void force_quiescent_state(struct rcu_state *rsp)
if (rnp_old != NULL)
raw_spin_unlock(&rnp_old->fqslock);
if (ret) {
rsp->n_force_qs_lh++;
ACCESS_ONCE(rsp->n_force_qs_lh)++;
return;
}
rnp_old = rnp;
@ -2316,7 +2314,7 @@ static void force_quiescent_state(struct rcu_state *rsp)
smp_mb__after_unlock_lock();
raw_spin_unlock(&rnp_old->fqslock);
if (ACCESS_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
rsp->n_force_qs_lh++;
ACCESS_ONCE(rsp->n_force_qs_lh)++;
raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
return; /* Someone beat us to it. */
}
@ -2880,7 +2878,7 @@ static int rcu_pending(int cpu)
* non-NULL, store an indication of whether all callbacks are lazy.
* (If there are no callbacks, all of them are deemed to be lazy.)
*/
static int rcu_cpu_has_callbacks(int cpu, bool *all_lazy)
static int __maybe_unused rcu_cpu_has_callbacks(int cpu, bool *all_lazy)
{
bool al = true;
bool hc = false;

View File

@ -13,8 +13,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2008
*

View File

@ -14,8 +14,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright Red Hat, 2009
* Copyright IBM Corporation, 2009
@ -1586,11 +1586,13 @@ static void rcu_prepare_kthreads(int cpu)
* Because we not have RCU_FAST_NO_HZ, just check whether this CPU needs
* any flavor of RCU.
*/
#ifndef CONFIG_RCU_NOCB_CPU_ALL
int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
{
*delta_jiffies = ULONG_MAX;
return rcu_cpu_has_callbacks(cpu, NULL);
}
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
/*
* Because we do not have RCU_FAST_NO_HZ, don't bother cleaning up
@ -1656,7 +1658,7 @@ extern int tick_nohz_active;
* only if it has been awhile since the last time we did so. Afterwards,
* if there are any callbacks ready for immediate invocation, return true.
*/
static bool rcu_try_advance_all_cbs(void)
static bool __maybe_unused rcu_try_advance_all_cbs(void)
{
bool cbs_ready = false;
struct rcu_data *rdp;
@ -1696,6 +1698,7 @@ static bool rcu_try_advance_all_cbs(void)
*
* The caller must have disabled interrupts.
*/
#ifndef CONFIG_RCU_NOCB_CPU_ALL
int rcu_needs_cpu(int cpu, unsigned long *dj)
{
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
@ -1726,6 +1729,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj)
}
return 0;
}
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
/*
* Prepare a CPU for idle from an RCU perspective. The first major task
@ -1739,6 +1743,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj)
*/
static void rcu_prepare_for_idle(int cpu)
{
#ifndef CONFIG_RCU_NOCB_CPU_ALL
struct rcu_data *rdp;
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
struct rcu_node *rnp;
@ -1790,6 +1795,7 @@ static void rcu_prepare_for_idle(int cpu)
rcu_accelerate_cbs(rsp, rnp, rdp);
raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
}
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
}
/*
@ -1799,11 +1805,12 @@ static void rcu_prepare_for_idle(int cpu)
*/
static void rcu_cleanup_after_idle(int cpu)
{
#ifndef CONFIG_RCU_NOCB_CPU_ALL
if (rcu_is_nocb_cpu(cpu))
return;
if (rcu_try_advance_all_cbs())
invoke_rcu_core();
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
}
/*
@ -2101,6 +2108,7 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
init_waitqueue_head(&rnp->nocb_gp_wq[1]);
}
#ifndef CONFIG_RCU_NOCB_CPU_ALL
/* Is the specified CPU a no-CPUs CPU? */
bool rcu_is_nocb_cpu(int cpu)
{
@ -2108,6 +2116,7 @@ bool rcu_is_nocb_cpu(int cpu)
return cpumask_test_cpu(cpu, rcu_nocb_mask);
return false;
}
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
/*
* Enqueue the specified string of rcu_head structures onto the specified
@ -2893,7 +2902,7 @@ static void rcu_sysidle_init_percpu_data(struct rcu_dynticks *rdtp)
* CPU unless the grace period has extended for too long.
*
* This code relies on the fact that all NO_HZ_FULL CPUs are also
* CONFIG_RCU_NOCB_CPUs.
* CONFIG_RCU_NOCB_CPU CPUs.
*/
static bool rcu_nohz_full_cpu(struct rcu_state *rsp)
{

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2008
*
@ -273,7 +273,7 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n",
rsp->n_force_qs, rsp->n_force_qs_ngp,
rsp->n_force_qs - rsp->n_force_qs_ngp,
rsp->n_force_qs_lh, rsp->qlen_lazy, rsp->qlen);
ACCESS_ONCE(rsp->n_force_qs_lh), rsp->qlen_lazy, rsp->qlen);
for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) {
if (rnp->level != level) {
seq_puts(m, "\n");

View File

@ -12,8 +12,8 @@
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2001
*
@ -49,7 +49,6 @@
#include <linux/module.h>
#define CREATE_TRACE_POINTS
#include <trace/events/rcu.h>
#include "rcu.h"

719
kernel/torture.c Normal file
View File

@ -0,0 +1,719 @@
/*
* Common functions for in-kernel torture tests.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright (C) IBM Corporation, 2014
*
* Author: Paul E. McKenney <paulmck@us.ibm.com>
* Based on kernel/rcu/torture.c.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/moduleparam.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/freezer.h>
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/trace_clock.h>
#include <asm/byteorder.h>
#include <linux/torture.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
static char *torture_type;
static bool verbose;
/* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */
#define FULLSTOP_DONTSTOP 0 /* Normal operation. */
#define FULLSTOP_SHUTDOWN 1 /* System shutdown with torture running. */
#define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */
static int fullstop = FULLSTOP_RMMOD;
static DEFINE_MUTEX(fullstop_mutex);
static int *torture_runnable;
#ifdef CONFIG_HOTPLUG_CPU
/*
* Variables for online-offline handling. Only present if CPU hotplug
* is enabled, otherwise does nothing.
*/
static struct task_struct *onoff_task;
static long onoff_holdoff;
static long onoff_interval;
static long n_offline_attempts;
static long n_offline_successes;
static unsigned long sum_offline;
static int min_offline = -1;
static int max_offline;
static long n_online_attempts;
static long n_online_successes;
static unsigned long sum_online;
static int min_online = -1;
static int max_online;
/*
* Execute random CPU-hotplug operations at the interval specified
* by the onoff_interval.
*/
static int
torture_onoff(void *arg)
{
int cpu;
unsigned long delta;
int maxcpu = -1;
DEFINE_TORTURE_RANDOM(rand);
int ret;
unsigned long starttime;
VERBOSE_TOROUT_STRING("torture_onoff task started");
for_each_online_cpu(cpu)
maxcpu = cpu;
WARN_ON(maxcpu < 0);
if (onoff_holdoff > 0) {
VERBOSE_TOROUT_STRING("torture_onoff begin holdoff");
schedule_timeout_interruptible(onoff_holdoff);
VERBOSE_TOROUT_STRING("torture_onoff end holdoff");
}
while (!torture_must_stop()) {
cpu = (torture_random(&rand) >> 4) % (maxcpu + 1);
if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) {
if (verbose)
pr_alert("%s" TORTURE_FLAG
"torture_onoff task: offlining %d\n",
torture_type, cpu);
starttime = jiffies;
n_offline_attempts++;
ret = cpu_down(cpu);
if (ret) {
if (verbose)
pr_alert("%s" TORTURE_FLAG
"torture_onoff task: offline %d failed: errno %d\n",
torture_type, cpu, ret);
} else {
if (verbose)
pr_alert("%s" TORTURE_FLAG
"torture_onoff task: offlined %d\n",
torture_type, cpu);
n_offline_successes++;
delta = jiffies - starttime;
sum_offline += delta;
if (min_offline < 0) {
min_offline = delta;
max_offline = delta;
}
if (min_offline > delta)
min_offline = delta;
if (max_offline < delta)
max_offline = delta;
}
} else if (cpu_is_hotpluggable(cpu)) {
if (verbose)
pr_alert("%s" TORTURE_FLAG
"torture_onoff task: onlining %d\n",
torture_type, cpu);
starttime = jiffies;
n_online_attempts++;
ret = cpu_up(cpu);
if (ret) {
if (verbose)
pr_alert("%s" TORTURE_FLAG
"torture_onoff task: online %d failed: errno %d\n",
torture_type, cpu, ret);
} else {
if (verbose)
pr_alert("%s" TORTURE_FLAG
"torture_onoff task: onlined %d\n",
torture_type, cpu);
n_online_successes++;
delta = jiffies - starttime;
sum_online += delta;
if (min_online < 0) {
min_online = delta;
max_online = delta;
}
if (min_online > delta)
min_online = delta;
if (max_online < delta)
max_online = delta;
}
}
schedule_timeout_interruptible(onoff_interval);
}
torture_kthread_stopping("torture_onoff");
return 0;
}
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
/*
* Initiate online-offline handling.
*/
int torture_onoff_init(long ooholdoff, long oointerval)
{
int ret = 0;
#ifdef CONFIG_HOTPLUG_CPU
onoff_holdoff = ooholdoff;
onoff_interval = oointerval;
if (onoff_interval <= 0)
return 0;
ret = torture_create_kthread(torture_onoff, NULL, onoff_task);
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
return ret;
}
EXPORT_SYMBOL_GPL(torture_onoff_init);
/*
* Clean up after online/offline testing.
*/
static void torture_onoff_cleanup(void)
{
#ifdef CONFIG_HOTPLUG_CPU
if (onoff_task == NULL)
return;
VERBOSE_TOROUT_STRING("Stopping torture_onoff task");
kthread_stop(onoff_task);
onoff_task = NULL;
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
}
EXPORT_SYMBOL_GPL(torture_onoff_cleanup);
/*
* Print online/offline testing statistics.
*/
char *torture_onoff_stats(char *page)
{
#ifdef CONFIG_HOTPLUG_CPU
page += sprintf(page,
"onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
n_online_successes, n_online_attempts,
n_offline_successes, n_offline_attempts,
min_online, max_online,
min_offline, max_offline,
sum_online, sum_offline, HZ);
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
return page;
}
EXPORT_SYMBOL_GPL(torture_onoff_stats);
/*
* Were all the online/offline operations successful?
*/
bool torture_onoff_failures(void)
{
#ifdef CONFIG_HOTPLUG_CPU
return n_online_successes != n_online_attempts ||
n_offline_successes != n_offline_attempts;
#else /* #ifdef CONFIG_HOTPLUG_CPU */
return false;
#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
}
EXPORT_SYMBOL_GPL(torture_onoff_failures);
#define TORTURE_RANDOM_MULT 39916801 /* prime */
#define TORTURE_RANDOM_ADD 479001701 /* prime */
#define TORTURE_RANDOM_REFRESH 10000
/*
* Crude but fast random-number generator. Uses a linear congruential
* generator, with occasional help from cpu_clock().
*/
unsigned long
torture_random(struct torture_random_state *trsp)
{
if (--trsp->trs_count < 0) {
trsp->trs_state += (unsigned long)local_clock();
trsp->trs_count = TORTURE_RANDOM_REFRESH;
}
trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT +
TORTURE_RANDOM_ADD;
return swahw32(trsp->trs_state);
}
EXPORT_SYMBOL_GPL(torture_random);
/*
* Variables for shuffling. The idea is to ensure that each CPU stays
* idle for an extended period to test interactions with dyntick idle,
* as well as interactions with any per-CPU varibles.
*/
struct shuffle_task {
struct list_head st_l;
struct task_struct *st_t;
};
static long shuffle_interval; /* In jiffies. */
static struct task_struct *shuffler_task;
static cpumask_var_t shuffle_tmp_mask;
static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */
static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list);
static DEFINE_MUTEX(shuffle_task_mutex);
/*
* Register a task to be shuffled. If there is no memory, just splat
* and don't bother registering.
*/
void torture_shuffle_task_register(struct task_struct *tp)
{
struct shuffle_task *stp;
if (WARN_ON_ONCE(tp == NULL))
return;
stp = kmalloc(sizeof(*stp), GFP_KERNEL);
if (WARN_ON_ONCE(stp == NULL))
return;
stp->st_t = tp;
mutex_lock(&shuffle_task_mutex);
list_add(&stp->st_l, &shuffle_task_list);
mutex_unlock(&shuffle_task_mutex);
}
EXPORT_SYMBOL_GPL(torture_shuffle_task_register);
/*
* Unregister all tasks, for example, at the end of the torture run.
*/
static void torture_shuffle_task_unregister_all(void)
{
struct shuffle_task *stp;
struct shuffle_task *p;
mutex_lock(&shuffle_task_mutex);
list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) {
list_del(&stp->st_l);
kfree(stp);
}
mutex_unlock(&shuffle_task_mutex);
}
/* Shuffle tasks such that we allow shuffle_idle_cpu to become idle.
* A special case is when shuffle_idle_cpu = -1, in which case we allow
* the tasks to run on all CPUs.
*/
static void torture_shuffle_tasks(void)
{
struct shuffle_task *stp;
cpumask_setall(shuffle_tmp_mask);
get_online_cpus();
/* No point in shuffling if there is only one online CPU (ex: UP) */
if (num_online_cpus() == 1) {
put_online_cpus();
return;
}
/* Advance to the next CPU. Upon overflow, don't idle any CPUs. */
shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask);
if (shuffle_idle_cpu >= nr_cpu_ids)
shuffle_idle_cpu = -1;
if (shuffle_idle_cpu != -1) {
cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask);
if (cpumask_empty(shuffle_tmp_mask)) {
put_online_cpus();
return;
}
}
mutex_lock(&shuffle_task_mutex);
list_for_each_entry(stp, &shuffle_task_list, st_l)
set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask);
mutex_unlock(&shuffle_task_mutex);
put_online_cpus();
}
/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
* system to become idle at a time and cut off its timer ticks. This is meant
* to test the support for such tickless idle CPU in RCU.
*/
static int torture_shuffle(void *arg)
{
VERBOSE_TOROUT_STRING("torture_shuffle task started");
do {
schedule_timeout_interruptible(shuffle_interval);
torture_shuffle_tasks();
torture_shutdown_absorb("torture_shuffle");
} while (!torture_must_stop());
torture_kthread_stopping("torture_shuffle");
return 0;
}
/*
* Start the shuffler, with shuffint in jiffies.
*/
int torture_shuffle_init(long shuffint)
{
shuffle_interval = shuffint;
shuffle_idle_cpu = -1;
if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) {
VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask");
return -ENOMEM;
}
/* Create the shuffler thread */
return torture_create_kthread(torture_shuffle, NULL, shuffler_task);
}
EXPORT_SYMBOL_GPL(torture_shuffle_init);
/*
* Stop the shuffling.
*/
static void torture_shuffle_cleanup(void)
{
torture_shuffle_task_unregister_all();
if (shuffler_task) {
VERBOSE_TOROUT_STRING("Stopping torture_shuffle task");
kthread_stop(shuffler_task);
free_cpumask_var(shuffle_tmp_mask);
}
shuffler_task = NULL;
}
EXPORT_SYMBOL_GPL(torture_shuffle_cleanup);
/*
* Variables for auto-shutdown. This allows "lights out" torture runs
* to be fully scripted.
*/
static int shutdown_secs; /* desired test duration in seconds. */
static struct task_struct *shutdown_task;
static unsigned long shutdown_time; /* jiffies to system shutdown. */
static void (*torture_shutdown_hook)(void);
/*
* Absorb kthreads into a kernel function that won't return, so that
* they won't ever access module text or data again.
*/
void torture_shutdown_absorb(const char *title)
{
while (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
pr_notice("torture thread %s parking due to system shutdown\n",
title);
schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
}
}
EXPORT_SYMBOL_GPL(torture_shutdown_absorb);
/*
* Cause the torture test to shutdown the system after the test has
* run for the time specified by the shutdown_secs parameter.
*/
static int torture_shutdown(void *arg)
{
long delta;
unsigned long jiffies_snap;
VERBOSE_TOROUT_STRING("torture_shutdown task started");
jiffies_snap = jiffies;
while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
!torture_must_stop()) {
delta = shutdown_time - jiffies_snap;
if (verbose)
pr_alert("%s" TORTURE_FLAG
"torture_shutdown task: %lu jiffies remaining\n",
torture_type, delta);
schedule_timeout_interruptible(delta);
jiffies_snap = jiffies;
}
if (torture_must_stop()) {
torture_kthread_stopping("torture_shutdown");
return 0;
}
/* OK, shut down the system. */
VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system");
shutdown_task = NULL; /* Avoid self-kill deadlock. */
if (torture_shutdown_hook)
torture_shutdown_hook();
else
VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping.");
kernel_power_off(); /* Shut down the system. */
return 0;
}
/*
* Start up the shutdown task.
*/
int torture_shutdown_init(int ssecs, void (*cleanup)(void))
{
int ret = 0;
shutdown_secs = ssecs;
torture_shutdown_hook = cleanup;
if (shutdown_secs > 0) {
shutdown_time = jiffies + shutdown_secs * HZ;
ret = torture_create_kthread(torture_shutdown, NULL,
shutdown_task);
}
return ret;
}
EXPORT_SYMBOL_GPL(torture_shutdown_init);
/*
* Detect and respond to a system shutdown.
*/
static int torture_shutdown_notify(struct notifier_block *unused1,
unsigned long unused2, void *unused3)
{
mutex_lock(&fullstop_mutex);
if (ACCESS_ONCE(fullstop) == FULLSTOP_DONTSTOP) {
VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected");
ACCESS_ONCE(fullstop) = FULLSTOP_SHUTDOWN;
} else {
pr_warn("Concurrent rmmod and shutdown illegal!\n");
}
mutex_unlock(&fullstop_mutex);
return NOTIFY_DONE;
}
static struct notifier_block torture_shutdown_nb = {
.notifier_call = torture_shutdown_notify,
};
/*
* Shut down the shutdown task. Say what??? Heh! This can happen if
* the torture module gets an rmmod before the shutdown time arrives. ;-)
*/
static void torture_shutdown_cleanup(void)
{
unregister_reboot_notifier(&torture_shutdown_nb);
if (shutdown_task != NULL) {
VERBOSE_TOROUT_STRING("Stopping torture_shutdown task");
kthread_stop(shutdown_task);
}
shutdown_task = NULL;
}
/*
* Variables for stuttering, which means to periodically pause and
* restart testing in order to catch bugs that appear when load is
* suddenly applied to or removed from the system.
*/
static struct task_struct *stutter_task;
static int stutter_pause_test;
static int stutter;
/*
* Block until the stutter interval ends. This must be called periodically
* by all running kthreads that need to be subject to stuttering.
*/
void stutter_wait(const char *title)
{
while (ACCESS_ONCE(stutter_pause_test) ||
(torture_runnable && !ACCESS_ONCE(*torture_runnable))) {
if (stutter_pause_test)
schedule_timeout_interruptible(1);
else
schedule_timeout_interruptible(round_jiffies_relative(HZ));
torture_shutdown_absorb(title);
}
}
EXPORT_SYMBOL_GPL(stutter_wait);
/*
* Cause the torture test to "stutter", starting and stopping all
* threads periodically.
*/
static int torture_stutter(void *arg)
{
VERBOSE_TOROUT_STRING("torture_stutter task started");
do {
if (!torture_must_stop()) {
schedule_timeout_interruptible(stutter);
ACCESS_ONCE(stutter_pause_test) = 1;
}
if (!torture_must_stop())
schedule_timeout_interruptible(stutter);
ACCESS_ONCE(stutter_pause_test) = 0;
torture_shutdown_absorb("torture_stutter");
} while (!torture_must_stop());
torture_kthread_stopping("torture_stutter");
return 0;
}
/*
* Initialize and kick off the torture_stutter kthread.
*/
int torture_stutter_init(int s)
{
int ret;
stutter = s;
ret = torture_create_kthread(torture_stutter, NULL, stutter_task);
return ret;
}
EXPORT_SYMBOL_GPL(torture_stutter_init);
/*
* Cleanup after the torture_stutter kthread.
*/
static void torture_stutter_cleanup(void)
{
if (!stutter_task)
return;
VERBOSE_TOROUT_STRING("Stopping torture_stutter task");
kthread_stop(stutter_task);
stutter_task = NULL;
}
/*
* Initialize torture module. Please note that this is -not- invoked via
* the usual module_init() mechanism, but rather by an explicit call from
* the client torture module. This call must be paired with a later
* torture_init_end().
*
* The runnable parameter points to a flag that controls whether or not
* the test is currently runnable. If there is no such flag, pass in NULL.
*/
void __init torture_init_begin(char *ttype, bool v, int *runnable)
{
mutex_lock(&fullstop_mutex);
torture_type = ttype;
verbose = v;
torture_runnable = runnable;
fullstop = FULLSTOP_DONTSTOP;
}
EXPORT_SYMBOL_GPL(torture_init_begin);
/*
* Tell the torture module that initialization is complete.
*/
void __init torture_init_end(void)
{
mutex_unlock(&fullstop_mutex);
register_reboot_notifier(&torture_shutdown_nb);
}
EXPORT_SYMBOL_GPL(torture_init_end);
/*
* Clean up torture module. Please note that this is -not- invoked via
* the usual module_exit() mechanism, but rather by an explicit call from
* the client torture module. Returns true if a race with system shutdown
* is detected, otherwise, all kthreads started by functions in this file
* will be shut down.
*
* This must be called before the caller starts shutting down its own
* kthreads.
*/
bool torture_cleanup(void)
{
mutex_lock(&fullstop_mutex);
if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
pr_warn("Concurrent rmmod and shutdown illegal!\n");
mutex_unlock(&fullstop_mutex);
schedule_timeout_uninterruptible(10);
return true;
}
ACCESS_ONCE(fullstop) = FULLSTOP_RMMOD;
mutex_unlock(&fullstop_mutex);
torture_shutdown_cleanup();
torture_shuffle_cleanup();
torture_stutter_cleanup();
torture_onoff_cleanup();
return false;
}
EXPORT_SYMBOL_GPL(torture_cleanup);
/*
* Is it time for the current torture test to stop?
*/
bool torture_must_stop(void)
{
return torture_must_stop_irq() || kthread_should_stop();
}
EXPORT_SYMBOL_GPL(torture_must_stop);
/*
* Is it time for the current torture test to stop? This is the irq-safe
* version, hence no check for kthread_should_stop().
*/
bool torture_must_stop_irq(void)
{
return ACCESS_ONCE(fullstop) != FULLSTOP_DONTSTOP;
}
EXPORT_SYMBOL_GPL(torture_must_stop_irq);
/*
* Each kthread must wait for kthread_should_stop() before returning from
* its top-level function, otherwise segfaults ensue. This function
* prints a "stopping" message and waits for kthread_should_stop(), and
* should be called from all torture kthreads immediately prior to
* returning.
*/
void torture_kthread_stopping(char *title)
{
if (verbose)
VERBOSE_TOROUT_STRING(title);
while (!kthread_should_stop()) {
torture_shutdown_absorb(title);
schedule_timeout_uninterruptible(1);
}
}
EXPORT_SYMBOL_GPL(torture_kthread_stopping);
/*
* Create a generic torture kthread that is immediately runnable. If you
* need the kthread to be stopped so that you can do something to it before
* it starts, you will need to open-code your own.
*/
int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
char *f, struct task_struct **tp)
{
int ret = 0;
VERBOSE_TOROUT_STRING(m);
*tp = kthread_run(fn, arg, s);
if (IS_ERR(*tp)) {
ret = PTR_ERR(*tp);
VERBOSE_TOROUT_ERRSTRING(f);
*tp = NULL;
}
torture_shuffle_task_register(*tp);
return ret;
}
EXPORT_SYMBOL_GPL(_torture_create_kthread);
/*
* Stop a generic kthread, emitting a message.
*/
void _torture_stop_kthread(char *m, struct task_struct **tp)
{
if (*tp == NULL)
return;
VERBOSE_TOROUT_STRING(m);
kthread_stop(*tp);
*tp = NULL;
}
EXPORT_SYMBOL_GPL(_torture_stop_kthread);

View File

@ -980,6 +980,21 @@ config DEBUG_LOCKING_API_SELFTESTS
The following locking APIs are covered: spinlocks, rwlocks,
mutexes and rwsems.
config LOCK_TORTURE_TEST
tristate "torture tests for locking"
depends on DEBUG_KERNEL
select TORTURE_TEST
default n
help
This option provides a kernel module that runs torture tests
on kernel locking primitives. The kernel module may be built
after the fact on the running kernel to be tested, if desired.
Say Y here if you want kernel locking-primitive torture tests
to be built into the kernel.
Say M if you want these torture tests to build as a module.
Say N if you are unsure.
endmenu # lock debugging
config TRACE_IRQFLAGS
@ -1141,9 +1156,14 @@ config SPARSE_RCU_POINTER
Say N if you are unsure.
config TORTURE_TEST
tristate
default n
config RCU_TORTURE_TEST
tristate "torture tests for RCU"
depends on DEBUG_KERNEL
select TORTURE_TEST
default n
help
This option provides a kernel module that runs torture tests

View File

@ -96,6 +96,7 @@ identify_qemu () {
echo qemu-system-ppc64
else
echo Cannot figure out what qemu command to use! 1>&2
echo file $1 output: $u
# Usually this will be one of /usr/bin/qemu-system-*
# Use RCU_QEMU_CMD environment variable or appropriate
# argument to top-level script.

View File

@ -0,0 +1,51 @@
#!/bin/bash
#
# Analyze a given results directory for locktorture progress.
#
# Usage: sh kvm-recheck-lock.sh resdir
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, you can access it online at
# http://www.gnu.org/licenses/gpl-2.0.html.
#
# Copyright (C) IBM Corporation, 2014
#
# Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
i="$1"
if test -d $i
then
:
else
echo Unreadable results directory: $i
exit 1
fi
configfile=`echo $i | sed -e 's/^.*\///'`
ncs=`grep "Writes: Total:" $i/console.log 2> /dev/null | tail -1 | sed -e 's/^.* Total: //' -e 's/ .*$//'`
if test -z "$ncs"
then
echo $configfile
else
title="$configfile ------- $ncs acquisitions/releases"
dur=`sed -e 's/^.* locktorture.shutdown_secs=//' -e 's/ .*$//' < $i/qemu-cmd 2> /dev/null`
if test -z "$dur"
then
:
else
ncsps=`awk -v ncs=$ncs -v dur=$dur '
BEGIN { print ncs / dur }' < /dev/null`
title="$title ($ncsps per second)"
fi
echo $title
fi

View File

@ -0,0 +1,51 @@
#!/bin/bash
#
# Analyze a given results directory for rcutorture progress.
#
# Usage: sh kvm-recheck-rcu.sh resdir
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, you can access it online at
# http://www.gnu.org/licenses/gpl-2.0.html.
#
# Copyright (C) IBM Corporation, 2014
#
# Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
i="$1"
if test -d $i
then
:
else
echo Unreadable results directory: $i
exit 1
fi
configfile=`echo $i | sed -e 's/^.*\///'`
ngps=`grep ver: $i/console.log 2> /dev/null | tail -1 | sed -e 's/^.* ver: //' -e 's/ .*$//'`
if test -z "$ngps"
then
echo $configfile
else
title="$configfile ------- $ngps grace periods"
dur=`sed -e 's/^.* rcutorture.shutdown_secs=//' -e 's/ .*$//' < $i/qemu-cmd 2> /dev/null`
if test -z "$dur"
then
:
else
ngpsps=`awk -v ngps=$ngps -v dur=$dur '
BEGIN { print ngps / dur }' < /dev/null`
title="$title ($ngpsps per second)"
fi
echo $title
fi

View File

@ -1,6 +1,6 @@
#!/bin/bash
#
# Given the results directories for previous KVM runs of rcutorture,
# Given the results directories for previous KVM-based torture runs,
# check the build and console output for errors. Given a directory
# containing results directories, this recursively checks them all.
#
@ -27,11 +27,18 @@
PATH=`pwd`/tools/testing/selftests/rcutorture/bin:$PATH; export PATH
for rd in "$@"
do
firsttime=1
dirs=`find $rd -name Make.defconfig.out -print | sort | sed -e 's,/[^/]*$,,' | sort -u`
for i in $dirs
do
configfile=`echo $i | sed -e 's/^.*\///'`
echo $configfile
if test -n "$firsttime"
then
firsttime=""
resdir=`echo $i | sed -e 's,/$,,' -e 's,/[^/]*$,,'`
head -1 $resdir/log
fi
TORTURE_SUITE="`cat $i/../TORTURE_SUITE`"
kvm-recheck-${TORTURE_SUITE}.sh $i
configcheck.sh $i/.config $i/ConfigFragment
parse-build.sh $i/Make.out $configfile
parse-rcutorture.sh $i/console.log $configfile

View File

@ -6,15 +6,15 @@
# Execute this in the source tree. Do not run it as a background task
# because qemu does not seem to like that much.
#
# Usage: sh kvm-test-1-rcu.sh config builddir resdir minutes qemu-args bootargs
# Usage: sh kvm-test-1-run.sh config builddir resdir minutes qemu-args boot_args
#
# qemu-args defaults to "" -- you will want "-nographic" if running headless.
# bootargs defaults to "root=/dev/sda noapic selinux=0 console=ttyS0"
# "initcall_debug debug rcutorture.stat_interval=15"
# "rcutorture.shutdown_secs=$((minutes * 60))"
# "rcutorture.rcutorture_runnable=1"
# qemu-args defaults to "-nographic", along with arguments specifying the
# number of CPUs and other options generated from
# the underlying CPU architecture.
# boot_args defaults to value returned by the per_version_boot_params
# shell function.
#
# Anything you specify for either qemu-args or bootargs is appended to
# Anything you specify for either qemu-args or boot_args is appended to
# the default values. The "-smp" value is deduced from the contents of
# the config fragment.
#
@ -40,32 +40,34 @@
grace=120
T=/tmp/kvm-test-1-rcu.sh.$$
T=/tmp/kvm-test-1-run.sh.$$
trap 'rm -rf $T' 0
. $KVM/bin/functions.sh
. $KVPATH/ver_functions.sh
config_template=${1}
config_dir=`echo $config_template | sed -e 's,/[^/]*$,,'`
title=`echo $config_template | sed -e 's/^.*\///'`
builddir=${2}
if test -z "$builddir" -o ! -d "$builddir" -o ! -w "$builddir"
then
echo "kvm-test-1-rcu.sh :$builddir: Not a writable directory, cannot build into it"
echo "kvm-test-1-run.sh :$builddir: Not a writable directory, cannot build into it"
exit 1
fi
resdir=${3}
if test -z "$resdir" -o ! -d "$resdir" -o ! -w "$resdir"
then
echo "kvm-test-1-rcu.sh :$resdir: Not a writable directory, cannot build into it"
echo "kvm-test-1-run.sh :$resdir: Not a writable directory, cannot store results into it"
exit 1
fi
cp $config_template $resdir/ConfigFragment
echo ' ---' `date`: Starting build
echo ' ---' Kconfig fragment at: $config_template >> $resdir/log
cat << '___EOF___' >> $T
CONFIG_RCU_TORTURE_TEST=y
___EOF___
if test -r "$config_dir/CFcommon"
then
cat < $config_dir/CFcommon >> $T
fi
# Optimizations below this point
# CONFIG_USB=n
# CONFIG_SECURITY=n
@ -96,11 +98,23 @@ then
cp $builddir/.config $resdir
cp $builddir/arch/x86/boot/bzImage $resdir
parse-build.sh $resdir/Make.out $title
if test -f $builddir.wait
then
mv $builddir.wait $builddir.ready
fi
else
cp $builddir/Make*.out $resdir
echo Build failed, not running KVM, see $resdir.
if test -f $builddir.wait
then
mv $builddir.wait $builddir.ready
fi
exit 1
fi
while test -f $builddir.ready
do
sleep 1
done
minutes=$4
seconds=$(($minutes * 60))
qemu_args=$5
@ -111,9 +125,10 @@ kstarttime=`awk 'BEGIN { print systime() }' < /dev/null`
echo ' ---' `date`: Starting kernel
# Determine the appropriate flavor of qemu command.
QEMU="`identify_qemu $builddir/vmlinux.o`"
QEMU="`identify_qemu $builddir/vmlinux`"
# Generate -smp qemu argument.
qemu_args="-nographic $qemu_args"
cpu_count=`configNR_CPUS.sh $config_template`
vcpus=`identify_qemu_vcpus`
if test $cpu_count -gt $vcpus
@ -133,12 +148,8 @@ qemu_append="`identify_qemu_append "$QEMU"`"
# Pull in Kconfig-fragment boot parameters
boot_args="`configfrag_boot_params "$boot_args" "$config_template"`"
# Generate CPU-hotplug boot parameters
boot_args="`rcutorture_param_onoff "$boot_args" $builddir/.config`"
# Generate rcu_barrier() boot parameter
boot_args="`rcutorture_param_n_barrier_cbs "$boot_args"`"
# Pull in standard rcutorture boot arguments
boot_args="$boot_args rcutorture.stat_interval=15 rcutorture.shutdown_secs=$seconds rcutorture.rcutorture_runnable=1"
# Generate kernel-version-specific boot parameters
boot_args="`per_version_boot_params "$boot_args" $builddir/.config $seconds`"
echo $QEMU $qemu_args -m 512 -kernel $builddir/arch/x86/boot/bzImage -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd
if test -n "$RCU_BUILDONLY"
@ -188,5 +199,5 @@ then
fi
cp $builddir/console.log $resdir
parse-rcutorture.sh $resdir/console.log $title
parse-${TORTURE_SUITE}torture.sh $resdir/console.log $title
parse-console.sh $resdir/console.log $title

View File

@ -30,14 +30,21 @@
scriptname=$0
args="$*"
T=/tmp/kvm.sh.$$
trap 'rm -rf $T' 0
mkdir $T
dur=30
dryrun=""
KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
PATH=${KVM}/bin:$PATH; export PATH
builddir="${KVM}/b1"
RCU_INITRD="$KVM/initrd"; export RCU_INITRD
RCU_KMAKE_ARG=""; export RCU_KMAKE_ARG
TORTURE_SUITE=rcu
resdir=""
configs=""
cpus=0
ds=`date +%Y.%m.%d-%H:%M:%S`
kversion=""
@ -49,7 +56,9 @@ usage () {
echo " --builddir absolute-pathname"
echo " --buildonly"
echo " --configs \"config-file list\""
echo " --cpus N"
echo " --datestamp string"
echo " --dryrun sched|script"
echo " --duration minutes"
echo " --interactive"
echo " --kmake-arg kernel-make-arguments"
@ -58,8 +67,9 @@ usage () {
echo " --no-initrd"
echo " --qemu-args qemu-system-..."
echo " --qemu-cmd qemu-system-..."
echo " --results absolute-pathname"
echo " --relbuilddir relative-pathname"
echo " --results absolute-pathname"
echo " --torture rcu"
exit 1
}
@ -85,11 +95,21 @@ do
configs="$2"
shift
;;
--cpus)
checkarg --cpus "(number)" "$#" "$2" '^[0-9]*$' '^--'
cpus=$2
shift
;;
--datestamp)
checkarg --datestamp "(relative pathname)" "$#" "$2" '^[^/]*$' '^--'
ds=$2
shift
;;
--dryrun)
checkarg --dryrun "sched|script" $# "$2" 'sched\|script' '^--'
dryrun=$2
shift
;;
--duration)
checkarg --duration "(minutes)" $# "$2" '^[0-9]*$' '^error'
dur=$2
@ -138,6 +158,11 @@ do
resdir=$2
shift
;;
--torture)
checkarg --torture "(suite name)" "$#" "$2" '^\(lock\|rcu\)$' '^--'
TORTURE_SUITE=$2
shift
;;
*)
echo Unknown argument $1
usage
@ -146,7 +171,7 @@ do
shift
done
CONFIGFRAG=${KVM}/configs; export CONFIGFRAG
CONFIGFRAG=${KVM}/configs/${TORTURE_SUITE}; export CONFIGFRAG
KVPATH=${CONFIGFRAG}/$kversion; export KVPATH
if test -z "$configs"
@ -157,54 +182,231 @@ fi
if test -z "$resdir"
then
resdir=$KVM/res
if ! test -e $resdir
then
mkdir $resdir || :
fi
else
fi
if test "$dryrun" = ""
then
if ! test -e $resdir
then
mkdir -p "$resdir" || :
fi
fi
mkdir $resdir/$ds
touch $resdir/$ds/log
echo $scriptname $args >> $resdir/$ds/log
mkdir $resdir/$ds
pwd > $resdir/$ds/testid.txt
if test -d .git
then
git status >> $resdir/$ds/testid.txt
git rev-parse HEAD >> $resdir/$ds/testid.txt
fi
builddir=$KVM/b1
if ! test -e $builddir
then
mkdir $builddir || :
# Be noisy only if running the script.
echo Results directory: $resdir/$ds
echo $scriptname $args
touch $resdir/$ds/log
echo $scriptname $args >> $resdir/$ds/log
echo ${TORTURE_SUITE} > $resdir/$ds/TORTURE_SUITE
pwd > $resdir/$ds/testid.txt
if test -d .git
then
git status >> $resdir/$ds/testid.txt
git rev-parse HEAD >> $resdir/$ds/testid.txt
fi
fi
# Create a file of test-name/#cpus pairs, sorted by decreasing #cpus.
touch $T/cfgcpu
for CF in $configs
do
# Running TREE01 multiple times creates TREE01, TREE01.2, TREE01.3, ...
rd=$resdir/$ds/$CF
if test -d "${rd}"
if test -f "$CONFIGFRAG/$kversion/$CF"
then
n="`ls -d "${rd}"* | grep '\.[0-9]\+$' |
sed -e 's/^.*\.\([0-9]\+\)/\1/' |
sort -k1n | tail -1`"
if test -z "$n"
then
rd="${rd}.2"
else
n="`expr $n + 1`"
rd="${rd}.${n}"
fi
echo $CF `configNR_CPUS.sh $CONFIGFRAG/$kversion/$CF` >> $T/cfgcpu
else
echo "The --configs file $CF does not exist, terminating."
exit 1
fi
mkdir "${rd}"
echo Results directory: $rd
kvm-test-1-rcu.sh $CONFIGFRAG/$kversion/$CF $builddir $rd $dur "-nographic $RCU_QEMU_ARG" "rcutorture.test_no_idle_hz=1 rcutorture.verbose=1 $RCU_BOOTARGS"
done
sort -k2nr $T/cfgcpu > $T/cfgcpu.sort
# Use a greedy bin-packing algorithm, sorting the list accordingly.
awk < $T/cfgcpu.sort > $T/cfgcpu.pack -v ncpus=$cpus '
BEGIN {
njobs = 0;
}
{
# Read file of tests and corresponding required numbers of CPUs.
cf[njobs] = $1;
cpus[njobs] = $2;
njobs++;
}
END {
alldone = 0;
batch = 0;
nc = -1;
# Each pass through the following loop creates on test batch
# that can be executed concurrently given ncpus. Note that a
# given test that requires more than the available CPUs will run in
# their own batch. Such tests just have to make do with what
# is available.
while (nc != ncpus) {
batch++;
nc = ncpus;
# Each pass through the following loop considers one
# test for inclusion in the current batch.
for (i = 0; i < njobs; i++) {
if (done[i])
continue; # Already part of a batch.
if (nc >= cpus[i] || nc == ncpus) {
# This test fits into the current batch.
done[i] = batch;
nc -= cpus[i];
if (nc <= 0)
break; # Too-big test in its own batch.
}
}
}
# Dump out the tests in batch order.
for (b = 1; b <= batch; b++)
for (i = 0; i < njobs; i++)
if (done[i] == b)
print cf[i], cpus[i];
}'
# Generate a script to execute the tests in appropriate batches.
cat << ___EOF___ > $T/script
TORTURE_SUITE="$TORTURE_SUITE"; export TORTURE_SUITE
___EOF___
awk < $T/cfgcpu.pack \
-v CONFIGDIR="$CONFIGFRAG/$kversion/" \
-v KVM="$KVM" \
-v ncpus=$cpus \
-v rd=$resdir/$ds/ \
-v dur=$dur \
-v RCU_QEMU_ARG=$RCU_QEMU_ARG \
-v RCU_BOOTARGS=$RCU_BOOTARGS \
'BEGIN {
i = 0;
}
{
cf[i] = $1;
cpus[i] = $2;
i++;
}
# Dump out the scripting required to run one test batch.
function dump(first, pastlast)
{
print "echo ----Start batch: `date`";
print "echo ----Start batch: `date` >> " rd "/log";
jn=1
for (j = first; j < pastlast; j++) {
builddir=KVM "/b" jn
cpusr[jn] = cpus[j];
if (cfrep[cf[j]] == "") {
cfr[jn] = cf[j];
cfrep[cf[j]] = 1;
} else {
cfrep[cf[j]]++;
cfr[jn] = cf[j] "." cfrep[cf[j]];
}
if (cpusr[jn] > ncpus && ncpus != 0)
ovf = "(!)";
else
ovf = "";
print "echo ", cfr[jn], cpusr[jn] ovf ": Starting build. `date`";
print "echo ", cfr[jn], cpusr[jn] ovf ": Starting build. `date` >> " rd "/log";
print "rm -f " builddir ".*";
print "touch " builddir ".wait";
print "mkdir " builddir " > /dev/null 2>&1 || :";
print "mkdir " rd cfr[jn] " || :";
print "kvm-test-1-run.sh " CONFIGDIR cf[j], builddir, rd cfr[jn], dur " \"" RCU_QEMU_ARG "\" \"" RCU_BOOTARGS "\" > " rd cfr[jn] "/kvm-test-1-run.sh.out 2>&1 &"
print "echo ", cfr[jn], cpusr[jn] ovf ": Waiting for build to complete. `date`";
print "echo ", cfr[jn], cpusr[jn] ovf ": Waiting for build to complete. `date` >> " rd "/log";
print "while test -f " builddir ".wait"
print "do"
print "\tsleep 1"
print "done"
print "echo ", cfr[jn], cpusr[jn] ovf ": Build complete. `date`";
print "echo ", cfr[jn], cpusr[jn] ovf ": Build complete. `date` >> " rd "/log";
jn++;
}
for (j = 1; j < jn; j++) {
builddir=KVM "/b" j
print "rm -f " builddir ".ready"
print "echo ----", cfr[j], cpusr[j] ovf ": Starting kernel. `date`";
print "echo ----", cfr[j], cpusr[j] ovf ": Starting kernel. `date` >> " rd "/log";
}
print "wait"
print "echo ---- All kernel runs complete. `date`";
print "echo ---- All kernel runs complete. `date` >> " rd "/log";
for (j = 1; j < jn; j++) {
builddir=KVM "/b" j
print "echo ----", cfr[j], cpusr[j] ovf ": Build/run results:";
print "echo ----", cfr[j], cpusr[j] ovf ": Build/run results: >> " rd "/log";
print "cat " rd cfr[j] "/kvm-test-1-run.sh.out";
print "cat " rd cfr[j] "/kvm-test-1-run.sh.out >> " rd "/log";
}
}
END {
njobs = i;
nc = ncpus;
first = 0;
# Each pass through the following loop considers one test.
for (i = 0; i < njobs; i++) {
if (ncpus == 0) {
# Sequential test specified, each test its own batch.
dump(i, i + 1);
first = i;
} else if (nc < cpus[i] && i != 0) {
# Out of CPUs, dump out a batch.
dump(first, i);
first = i;
nc = ncpus;
}
# Account for the CPUs needed by the current test.
nc -= cpus[i];
}
# Dump the last batch.
if (ncpus != 0)
dump(first, i);
}' >> $T/script
if test "$dryrun" = script
then
# Dump out the script, but define the environment variables that
# it needs to run standalone.
echo CONFIGFRAG="$CONFIGFRAG; export CONFIGFRAG"
echo KVM="$KVM; export KVM"
echo KVPATH="$KVPATH; export KVPATH"
echo PATH="$PATH; export PATH"
echo RCU_BUILDONLY="$RCU_BUILDONLY; export RCU_BUILDONLY"
echo RCU_INITRD="$RCU_INITRD; export RCU_INITRD"
echo RCU_KMAKE_ARG="$RCU_KMAKE_ARG; export RCU_KMAKE_ARG"
echo RCU_QEMU_CMD="$RCU_QEMU_CMD; export RCU_QEMU_CMD"
echo RCU_QEMU_INTERACTIVE="$RCU_QEMU_INTERACTIVE; export RCU_QEMU_INTERACTIVE"
echo RCU_QEMU_MAC="$RCU_QEMU_MAC; export RCU_QEMU_MAC"
echo "mkdir -p "$resdir" || :"
echo "mkdir $resdir/$ds"
cat $T/script
exit 0
elif test "$dryrun" = sched
then
# Extract the test run schedule from the script.
egrep 'start batch|Starting build\.' $T/script |
sed -e 's/:.*$//' -e 's/^echo //'
exit 0
else
# Not a dryru, so run the script.
sh $T/script
fi
# Tracing: trace_event=rcu:rcu_grace_period,rcu:rcu_future_grace_period,rcu:rcu_grace_period_init,rcu:rcu_nocb_wake,rcu:rcu_preempt_task,rcu:rcu_unlock_preempted_task,rcu:rcu_quiescent_state_report,rcu:rcu_fqs,rcu:rcu_callback,rcu:rcu_kfree_callback,rcu:rcu_batch_start,rcu:rcu_invoke_callback,rcu:rcu_invoke_kfree_callback,rcu:rcu_batch_end,rcu:rcu_torture_read,rcu:rcu_barrier
echo
echo
echo " --- `date` Test summary:"
echo Results directory: $resdir/$ds
kvm-recheck.sh $resdir/$ds

View File

@ -0,0 +1,6 @@
CONFIG_SMP=y
CONFIG_NR_CPUS=4
CONFIG_HOTPLUG_CPU=y
CONFIG_PREEMPT_NONE=n
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=y

View File

@ -0,0 +1 @@
locktorture.torture_type=lock_busted

View File

@ -0,0 +1 @@
LOCK01

View File

@ -0,0 +1,2 @@
CONFIG_LOCK_TORTURE_TEST=y
CONFIG_PRINTK_TIME=y

View File

@ -0,0 +1,6 @@
CONFIG_SMP=y
CONFIG_NR_CPUS=8
CONFIG_HOTPLUG_CPU=y
CONFIG_PREEMPT_NONE=n
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=y

View File

@ -0,0 +1,43 @@
#!/bin/bash
#
# Kernel-version-dependent shell functions for the rest of the scripts.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, you can access it online at
# http://www.gnu.org/licenses/gpl-2.0.html.
#
# Copyright (C) IBM Corporation, 2014
#
# Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
# locktorture_param_onoff bootparam-string config-file
#
# Adds onoff locktorture module parameters to kernels having it.
locktorture_param_onoff () {
if ! bootparam_hotplug_cpu "$1" && configfrag_hotplug_cpu "$2"
then
echo CPU-hotplug kernel, adding locktorture onoff. 1>&2
echo locktorture.onoff_interval=3 locktorture.onoff_holdoff=30
fi
}
# per_version_boot_params bootparam-string config-file seconds
#
# Adds per-version torture-module parameters to kernels supporting them.
per_version_boot_params () {
echo $1 `locktorture_param_onoff "$1" "$2"` \
locktorture.stat_interval=15 \
locktorture.shutdown_secs=$3 \
locktorture.locktorture_runnable=1 \
locktorture.verbose=1
}

View File

@ -0,0 +1,7 @@
CONFIG_RCU_TRACE=n
CONFIG_SMP=y
CONFIG_NR_CPUS=4
CONFIG_HOTPLUG_CPU=y
CONFIG_PREEMPT_NONE=n
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=y

View File

@ -0,0 +1 @@
rcutorture.torture_type=rcu_busted

View File

@ -0,0 +1,2 @@
CONFIG_RCU_TORTURE_TEST=y
CONFIG_PRINTK_TIME=y

View File

@ -1,8 +1,7 @@
CONFIG_RCU_TRACE=n
CONFIG_SMP=y
CONFIG_NR_CPUS=8
CONFIG_NR_CPUS=4
CONFIG_HOTPLUG_CPU=y
CONFIG_PREEMPT_NONE=y
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=n
CONFIG_PRINTK_TIME=y

View File

@ -5,4 +5,3 @@ CONFIG_HOTPLUG_CPU=y
CONFIG_PREEMPT_NONE=n
CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=y
CONFIG_PRINTK_TIME=y

View File

@ -10,4 +10,3 @@ CONFIG_RCU_TRACE=n
CONFIG_DEBUG_LOCK_ALLOC=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PREEMPT_COUNT=n
CONFIG_PRINTK_TIME=y

View File

@ -10,4 +10,3 @@ CONFIG_RCU_TRACE=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PREEMPT_COUNT=y
CONFIG_PRINTK_TIME=y

View File

@ -20,4 +20,3 @@ CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PRINTK_TIME=y

View File

@ -7,7 +7,7 @@ CONFIG_PREEMPT=y
CONFIG_HZ_PERIODIC=n
CONFIG_NO_HZ_IDLE=y
CONFIG_NO_HZ_FULL=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_FAST_NO_HZ=n
CONFIG_RCU_TRACE=n
CONFIG_HOTPLUG_CPU=n
CONFIG_SUSPEND=n
@ -23,4 +23,3 @@ CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=y
CONFIG_RCU_BOOST=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PRINTK_TIME=y

View File

@ -20,4 +20,3 @@ CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=y
CONFIG_RCU_BOOST_PRIO=2
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PRINTK_TIME=y

View File

@ -22,4 +22,3 @@ CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=y
CONFIG_RCU_CPU_STALL_VERBOSE=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PRINTK_TIME=y

View File

@ -22,4 +22,3 @@ CONFIG_PROVE_RCU_DELAY=y
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PRINTK_TIME=y

View File

@ -23,4 +23,3 @@ CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_PRINTK_TIME=y

View File

@ -21,4 +21,3 @@ CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=y
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PRINTK_TIME=y

View File

@ -23,4 +23,3 @@ CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PRINTK_TIME=y

View File

@ -23,4 +23,3 @@ CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PRINTK_TIME=y

View File

@ -18,4 +18,3 @@ CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
CONFIG_PRINTK_TIME=y

View File

@ -20,16 +20,14 @@
#
# Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
# rcutorture_param_n_barrier_cbs bootparam-string
# per_version_boot_params bootparam-string config-file seconds
#
# Adds n_barrier_cbs rcutorture module parameter to kernels having it.
rcutorture_param_n_barrier_cbs () {
echo $1
}
# rcutorture_param_onoff bootparam-string config-file
#
# Adds onoff rcutorture module parameters to kernels having it.
rcutorture_param_onoff () {
echo $1
# Adds per-version torture-module parameters to kernels supporting them.
# Which old kernels do not.
per_version_boot_params () {
echo rcutorture.stat_interval=15 \
rcutorture.shutdown_secs=$3 \
rcutorture.rcutorture_runnable=1 \
rcutorture.test_no_idle_hz=1 \
rcutorture.verbose=1
}

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