Impact: add a generic printk() for tracing, like trace_printk()
trace_bprintk() uses the infrastructure to record events on ring_buffer.
[ fweisbec@gmail.com: ported to latest -tip, made it work if
!CONFIG_MODULES, never free the format strings from modules
because we can't keep track of them and conditionnaly create
the ftrace format strings section (reported by Steven Rostedt) ]
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1236356510-8381-4-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: save on memory for tracing
Current tracers are typically using a struct(like struct ftrace_entry,
struct ctx_switch_entry, struct special_entr etc...)to record a binary
event. These structs can only record a their own kind of events.
A new kind of tracer need a new struct and a lot of code too handle it.
So we need a generic binary record for events. This infrastructure
is for this purpose.
[fweisbec@gmail.com: rebase against latest -tip, make it safe while sched
tracing as reported by Steven Rostedt]
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1236356510-8381-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
An new optimization is making its way to ftrace. Its purpose is to
make trace_printk() consuming less memory and be faster.
Written by Lai Jiangshan, the approach is to delay the formatting
job from tracing time to output time.
Currently, a call to trace_printk() will format the whole string and
insert it into the ring buffer. Then you can read it on /debug/tracing/trace
file.
The new implementation stores the address of the format string and
the binary parameters into the ring buffer, making the packet more compact
and faster to insert.
Later, when the user exports the traces, the format string is retrieved
with the binary parameters and the formatting job is eventually done.
The new implementation rewrites a lot of format decoding bits from
vsnprintf() function, making now 3 differents functions to maintain
in their duplicated parts of printf format decoding bits.
Suggested by Ingo Molnar, this patch tries to factorize the most
possible common bits from these functions.
The real common part between them is the format decoding. Although
they do somewhat similar jobs, their way to export or import the parameters
is very different. Thus, only the decoding layer is extracted, unless you see
other parts that could be worth factorized.
Changes in V2:
- Address a suggestion from Linus to group the format_decode() parameters inside
a structure.
Changes in v3:
- Address other cleanups suggested by Ingo and Linus such as passing the
printf_spec struct to the format helpers: pointer()/number()/string()
Note that this struct is passed by copy and not by address. This is to
avoid side effects because these functions often change these values and the
changes shoudn't be persistant when a callee helper returns.
It would be too risky.
- Various cleanups (code alignement, switch/case instead of if/else fountains).
- Fix a bug that printed the first format specifier following a %p
Changes in v4:
- drop unapropriate const qualifier loss while casting fmt to a char *
(thanks to Vegard Nossum for having pointed this out).
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1236356510-8381-6-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: add new APIs for binary trace printk infrastructure
vbin_printf(): write args to binary buffer, string is copied
when "%s" is occurred.
bstr_printf(): read from binary buffer for args and format a string
[fweisbec@gmail.com: rebase]
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1236356510-8381-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Stephen Rothwell reported:
|Today's linux-next build (x86_64 allmodconfig) produced this warning:
|
|In file included from drivers/char/epca.c:49:
|drivers/char/digiFep1.h:7:1: warning: "GLOBAL" redefined
|In file included from include/linux/linkage.h:5,
| from include/linux/kernel.h:11,
| from arch/x86/include/asm/system.h:10,
| from arch/x86/include/asm/processor.h:17,
| from include/linux/prefetch.h:14,
| from include/linux/list.h:6,
| from include/linux/module.h:9,
| from drivers/char/epca.c:29:
|arch/x86/include/asm/linkage.h:55:1: warning: this is the location of the previous definition
|
|Probably introduced by commit 95695547a7
|("x86: asm linkage - introduce GLOBAL macro") from the x86 tree.
Any assembler specific snippets being placed in headers
are to be protected by __ASSEMBLY__. Fixed.
Also move __ALIGN definition under the same protection as well.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <20090306160833.GB7420@localhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use fixmaps instead of vmap/vunmap in text_poke() for avoiding
page allocation and delayed unmapping.
At the result of above change, text_poke() becomes atomic and can be called
from stop_machine() etc.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
LKML-Reference: <49B14352.2040705@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use the mutual exclusion provided by the text edit lock in alternatives code.
Since alternative_smp_* will be called from module init code, etc,
we'd better protect it from other subsystems.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <49B14332.9030109@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use the mutual exclusion provided by the text edit lock in the kprobes code. It
allows coherent manipulation of the kernel code by other subsystems.
Changelog:
Move the kernel_text_lock/unlock out of the for loops.
Use text_mutex directly instead of a function.
Remove whitespace modifications.
(note : kprobes_mutex is always taken outside of text_mutex)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <49B14306.2080202@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This is an architecture independant synchronization around kernel text
modifications through use of a global mutex.
A mutex has been chosen so that kprobes, the main user of this, can sleep
during memory allocation between the memory read of the instructions it
must replace and the memory write of the breakpoint.
Other user of this interface: immediate values.
Paravirt and alternatives are always done when SMP is inactive, so there
is no need to use locks.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
LKML-Reference: <49B142D8.7020601@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: code reorganization for later changes
Do fully free chunk reclamation using a work. This change is to
prepare for locking changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: code reorganization for later changes
Separate out chunk area map extension into a separate function -
pcpu_extend_area_map() - and call it directly from pcpu_alloc() such
that pcpu_alloc_area() is guaranteed to have enough area map slots on
invocation.
With this change, pcpu_alloc_area() does only area allocation and the
only failure mode is when the chunk doens't have enough room, so
there's no need to distinguish it from memory allocation failures.
Make it return -1 on such cases instead of hacky -ENOSPC.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: code reorganization for later changes
With static map handling moved to pcpu_split_block(), pcpu_realloc()
only clutters the code and it's also unsuitable for scheduled locking
changes. Implement and use pcpu_mem_alloc/free() instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
ds_write_config() can write the BTS as well as the PEBS part of
the DS config. ds_request_pebs() passes the wrong qualifier, which
results in the wrong configuration to be written.
Reported-by: Stephane Eranian <eranian@googlemail.com>
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090305085721.A22550@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In case a ptraced task is reaped (while the tracer is still attached),
ds_exit_thread() is called before ptrace_exit(). The latter will
release the bts_tracer and remove the thread's ds_ctx.
The former will WARN() if the context is not NULL.
Oleg Nesterov submitted patches that move ptrace_exit() before
exit_thread() and thus reverse the order of the above calls.
Remove the bad warning. I will add it again when Oleg's changes are in.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090305084954.A22000@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
As a preparational step for unifying noexec handling on 32-bit and 64-bit,
rename the do_not_nx variable to disable_nx on 64-bit.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <1236265497.31324.11.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix
The 'struct power_trace' definition is needed (for the event tracer) even if
the power-tracer plugin is turned off in the .config.
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <20090306104106.GF31042@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: make boot command line "memtest" do one loop by default
So don't need to guess many patterns in one loop.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B10532.3020105@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix deadlock while using set_ftrace_pid
Reproducer:
# cd /sys/kernel/debug/tracing
# echo $$ > set_ftrace_pid
then, console becomes hung.
Details:
when writing set_ftracepid, kernel callstack is following
ftrace_pid_write()
mutex_lock(&ftrace_lock);
ftrace_update_pid_func()
mutex_lock(&ftrace_lock);
mutex_unlock(&ftrace_lock);
mutex_unlock(&ftrace_lock);
then, system always deadlocks when ftrace_pid_write() is called.
In past days, ftrace_pid_write() used ftrace_start_lock, but
commit e6ea44e9b4 consolidated
ftrace_start_lock to ftrace_lock.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <20090306151155.0778.A69D9226@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The recent changes over the DAC detection mechanism in patch_sigmatel.c
breaks the HP detection on the machines with multiple HP jacks.
It's basically because of the workaround to support the multi-channel
output. Since the HP detection is more important feature, disable
the HP-swap workaroud temporarily.
Reference: Novell bnc#482052
https://bugzilla.novell.com/show_bug.cgi?id=482052
Signed-off-by: Takashi Iwai <tiwai@suse.de>
"Headphone Playback ..." appears twice in slave_vols[] and slave_sws[].
They should be "Headphone Playback2 ..."
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Commit 1e42807918 introduced a bug where we
don't get front/back segment sizes in the bio in blk_recount_segments().
Fix this by tracking the back bio as well as the front bio in
__blk_recalc_rq_segments(), this also cleans up the interface by getting
rid of the segment size pointer passing.
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Impact: fix relocation overflow during module load
x86_64 uses 32bit relocations for symbol access and static percpu
symbols whether in core or modules must be inside 2GB of the percpu
segement base which the dynamic percpu allocator doesn't guarantee.
This patch makes x86_64 reserve PERCPU_MODULE_RESERVE bytes in the
first chunk so that module percpu areas are always allocated from the
first chunk which is always inside the relocatable range.
This problem exists for any percpu allocator but is easily triggered
when using the embedding allocator because the second chunk is located
beyond 2GB on it.
This patch also changes the meaning of PERCPU_DYNAMIC_RESERVE such
that it only indicates the size of the area to reserve for dynamic
allocation as static and dynamic areas can be separate. New
PERCPU_DYNAMIC_RESERVED is increased by 4k for both 32 and 64bits as
the reserved area separation eats away some allocatable space and
having slightly more headroom (currently between 4 and 8k after
minimal boot sans module area) makes sense for common case
performance.
x86_32 can address anywhere from anywhere and doesn't need reserving.
Mike Galbraith first reported the problem first and bisected it to the
embedding percpu allocator commit.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Mike Galbraith <efault@gmx.de>
Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Impact: add reserved allocation functionality and use it for module
percpu variables
This patch implements reserved allocation from the first chunk. When
setting up the first chunk, arch can ask to set aside certain number
of bytes right after the core static area which is available only
through a separate reserved allocator. This will be used primarily
for module static percpu variables on architectures with limited
relocation range to ensure that the module perpcu symbols are inside
the relocatable range.
If reserved area is requested, the first chunk becomes reserved and
isn't available for regular allocation. If the first chunk also
includes piggy-back dynamic allocation area, a separate chunk mapping
the same region is created to serve dynamic allocation. The first one
is called static first chunk and the second dynamic first chunk.
Although they share the page map, their different area map
initializations guarantee they serve disjoint areas according to their
purposes.
If arch doesn't setup reserved area, reserved allocation is handled
like any other allocation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: allow sharing page map, no functional difference yet
Make chunk->page access indirect by adding a pointer and renaming the
actual array to page_ar. This will be used by future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: reduce unnecessary memory usage on certain configurations
Embedding percpu allocator allocates unit_size *
smp_num_possible_cpus() bytes consecutively and use it for the first
chunk. However, if the static area is small, this can result in
excessive prellocated free space in the first chunk due to
PCPU_MIN_UNIT_SIZE restriction.
This patch makes embedding percpu allocator preallocate only what's
necessary as described by PERPCU_DYNAMIC_RESERVE and return the
leftover to the bootmem allocator.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: argument semantic cleanup
In pcpu_setup_first_chunk(), zero @unit_size and @dyn_size meant
auto-sizing. It's okay for @unit_size as 0 doesn't make sense but 0
dynamic reserve size is valid. Alos, if arch @dyn_size is calculated
from other parameters, it might end up passing in 0 @dyn_size and
malfunction when the size is automatically adjusted.
This patch makes both @unit_size and @dyn_size ssize_t and use -1 for
auto sizing.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: no functional change
When the first chunk is created, its initial area map is not allocated
because kmalloc isn't online yet. The map is allocated and
initialized on the first allocation request on the chunk. This works
fine but the scattering of initialization logic between the init
function and allocation path is a bit confusing.
This patch makes the first chunk initialize and use minimal statically
allocated map from pcpu_setpu_first_chunk(). The map resizing path
still needs to handle this specially but it's more straight-forward
and gives more latitude to the init path. This will ease future
changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: cosmetic, preparation for future changes
Make the following renames in pcpur_setup_first_chunk() in preparation
for future changes.
* s/free_size/dyn_size/
* s/static_vm/first_vm/
* s/static_chunk/schunk/
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: cleaup
Make the following cleanups.
* There isn't much arch-specific about PERCPU_MODULE_RESERVE. Always
define it whether arch overrides PERCPU_ENOUGH_ROOM or not.
* blackfin overrides PERCPU_ENOUGH_ROOM to align static area size. Do
it by default.
* percpu allocation sizes doesn't have much to do with the page size.
Don't use PAGE_SHIFT in their definition.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bryan Wu <cooloney@kernel.org>
Impact: allow user apps to read binary format of basic ftrace entries
Currently, only defined raw events export their formats so a binary
reader can parse them. There's no reason that the default ftrace entries
can't export their formats.
This patch adds a subsystem called "ftrace" in the events directory
that includes the ftrace entries for basic ftrace recorded items.
These only have three files in the events directory:
type : printf
available_types : printf
format : format for the event entry
For example:
# cat /debug/tracing/events/ftrace/wakeup/format
name: wakeup
ID: 3
format:
field:unsigned char type; offset:0; size:1;
field:unsigned char flags; offset:1; size:1;
field:unsigned char preempt_count; offset:2; size:1;
field:int pid; offset:4; size:4;
field:int tgid; offset:8; size:4;
field:unsigned int prev_pid; offset:12; size:4;
field:unsigned char prev_prio; offset:16; size:1;
field:unsigned char prev_state; offset:17; size:1;
field:unsigned int next_pid; offset:20; size:4;
field:unsigned char next_prio; offset:24; size:1;
field:unsigned char next_state; offset:25; size:1;
field:unsigned int next_cpu; offset:28; size:4;
print fmt: "%u:%u:%u ==+ %u:%u:%u [%03u]"
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: clean up
Move the macro that creates the event format file to a separate header.
This will allow the default ftrace events to use this same macro
to create the formats to read those events.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: cleanup
All file_operations structures should be constant. No one is going to
change them.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Clean up menu structure, introduce TRACING_SUPPORT switch that signals
whether an architecture supports various instrumentation mechanisms.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
orion5x_wdt no longer compiled after the changes in commit
ebe35aff88 ("Orion: prepare for
runtime-determined timer tick rate").
The tick rate define (ORION5X_TCLK) was removed in favor of a runtime
detection. The quick fix is to add the define in the watchdog driver.
The fix is not correct for all supported orion5x platforms, but since
the supported platforms right now are 133 Mhz and 166 Mhz, it won't
be _that_ far off. ;-) A fix that uses the runtime-determined timer
tick rate will be applied later.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: Kristof Provost <kristof@sigsegv.be>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Nicolas Pitre <nico@cam.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Declare CFA specific identify data words 162 and 163 for future use.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
[bart: update patch summary/description]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Lai Jiangshan
Ingo Molnar
Frederic Weisbecker
Cyrill Gorcunov
Masami Hiramatsu
Mathieu Desnoyers
Tejun Heo
Markus Metzger
Pekka Enberg
Yinghai Lu
KOSAKI Motohiro
Takashi Iwai
Jens Axboe
Steven Rostedt
Wim Van Sebroeck
Michael Hennerich
Mike Frysinger
Sergei Shtylyov