Add the hardware interrupt number to the output of /proc/interrupts.
It is often important to have access to the hardware interrupt number because
it identifies exactly how an interrupt signal is wired up to the interrupt
controller. This is especially important when using irq_domains since irq
numbers get dynamically allocated in that case, and have no relation to the
actual hardware number.
Note: This output is currently conditional on whether or not the irq_domain
pointer is set; however hwirq could still be used without irq_domain. It
may be worthwhile to always output the hwirq number regardless of the
domain pointer.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Olof Johansson <olof@lixom.net>
Cc: Ben Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data. Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
commit 4b06042(bitmap, irq: add smp_affinity_list interface to
/proc/irq) causes the following warning:
[ 274.239500] WARNING: at fs/proc/generic.c:850 remove_proc_entry+0x24c/0x27a()
[ 274.251761] remove_proc_entry: removing non-empty directory 'irq/184',
leaking at least 'smp_affinity_list'
Remove the new file in the exit path.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Mike Travis <travis@sgi.com>
Link: http://lkml.kernel.org/r/4DDDE094.6050505@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Manually adjusting the smp_affinity for IRQ's becomes unwieldy when the
cpu count is large.
Setting smp affinity to cpus 256 to 263 would be:
echo 000000ff,00000000,00000000,00000000,00000000,00000000,00000000,00000000 > smp_affinity
instead of:
echo 256-263 > smp_affinity_list
Think about what it looks like for cpus around say, 4088 to 4095.
We already have many alternate "list" interfaces:
/sys/devices/system/cpu/cpuX/indexY/shared_cpu_list
/sys/devices/system/cpu/cpuX/topology/thread_siblings_list
/sys/devices/system/cpu/cpuX/topology/core_siblings_list
/sys/devices/system/node/nodeX/cpulist
/sys/devices/pci***/***/local_cpulist
Add a companion interface, smp_affinity_list to use cpu lists instead of
cpu maps. This conforms to other companion interfaces where both a map
and a list interface exists.
This required adding a bitmap_parselist_user() function in a manner
similar to the bitmap_parse_user() function.
[akpm@linux-foundation.org: make __bitmap_parselist() static]
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit ab7798ffcf ("genirq: Expand generic
show_interrupts()") added the Kconfig option GENERIC_IRQ_SHOW_LEVEL to
accomodate PowerPC, but this doesn't actually enable the functionality due
to a typo in the #ifdef check.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linux/PPC Development <linuxppc-dev@lists.ozlabs.org>
Link: http://lkml.kernel.org/r/%3Calpine.DEB.2.00.1104302251370.19068%40ayla.of.borg%3E
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The only subtle difference is that alpha uses ACTUAL_NR_IRQS and
prints the IRQF_DISABLED flag.
Change the generic implementation to deal with ACTUAL_NR_IRQS if
defined.
The IRQF_DISABLED printing is pointless, as we nowadays run all
interrupts with irqs disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Some archs want to print extra information for certain irq_chips which
is per irq and not per chip. Allow them to provide a chip callback to
print the chip name and the extra information.
PowerPC wants to print the LEVEL/EDGE type information. Make it configurable.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
chip implementations need to know about it. Keep status in sync until
all users are fixed.
Accessor function: irqd_is_setaffinity_pending(irqdata)
Coders who access them directly will be tracked down and slapped with
stinking trouts.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
All archs implement show_interrupts() in more or less the same
way. That's tons of duplicated code with different bugs with no
value. Implement a generic version and deprecate show_interrupts()
Unfortunately we need some ifdeffery for !GENERIC_HARDIRQ archs.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
While rumaging through arch code I found that there are a few
workarounds which deal with the fact that the initial affinity setting
from request_irq() copies the mask into irq_data->affinity before the
chip code is called. In the normal path we unconditionally copy the
mask when the chip code returns 0.
Copy after the code is called and add a return code
IRQ_SET_MASK_OK_NOCOPY for the chip functions, which prevents the
copy. That way we see the real mask when the chip function decided to
truncate it further as some arches do. IRQ_SET_MASK_OK is 0, which is
the current behaviour.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Since commit a1afb637(switch /proc/irq/*/spurious to seq_file) all
/proc/irq/XX/spurious files show the information of irq 0.
Current irq_spurious_proc_open() passes on NULL as the 3rd argument,
which is used as an IRQ number in irq_spurious_proc_show(), to the
single_open(). Because of this, all the /proc/irq/XX/spurious file
shows IRQ 0 information regardless of the IRQ number.
To fix the problem, irq_spurious_proc_open() must pass on the
appropreate data (IRQ number) to single_open().
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
LKML-Reference: <4CF4B778.90604@jp.fujitsu.com>
Cc: stable@kernel.org [2.6.33+]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
/proc/irq never removes any entries, but when irq descriptors can be
freed for real this is necessary. Otherwise we'd reference a freed
descriptor in /proc/irq/N
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Wrap the old chip function set_affinity() until the migration is
complete and the old chip functions are removed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.732894108@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Convert all references in the core code to orq, chip, handler_data,
chip_data, msi_desc, affinity to irq_data.*
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
When an interrupt is disabled and torn down, the CPU mask returned
through affinity_hint right now is all CPUs. Also, for drivers that
don't provide an affinity_hint mask, this can be misleading. There
should be no hint at all, meaning an empty CPU mask.
[ tglx: use zalloc_cpumask_var instead of clearing it under the lock ]
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Cc: davem@davemloft.net
Cc: arjan@linux.jf.intel.com
Cc: bhutchings@solarflare.com
LKML-Reference: <20100505205638.5426.87189.stgit@ppwaskie-hc2.jf.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds a cpumask affinity hint to the irq_desc structure,
along with a registration function and a read-only proc entry for each
interrupt.
This affinity_hint handle for each interrupt can be used by underlying
drivers that need a better mechanism to control interrupt affinity.
The underlying driver can register a cpumask for the interrupt, which
will allow the driver to provide the CPU mask for the interrupt to
anything that requests it. The intent is to extend the userspace
daemon, irqbalance, to help hint to it a preferred CPU mask to balance
the interrupt into.
[ tglx: Fixed compile warnings, added WARN_ON, made SMP only ]
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Cc: davem@davemloft.net
Cc: arjan@linux.jf.intel.com
Cc: bhutchings@solarflare.com
LKML-Reference: <20100430214445.3992.41647.stgit@ppwaskie-hc2.jf.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Expose irq_desc->node as /proc/irq/*/node.
This file provides device hardware locality information for apps
desiring to include hardware locality in irq mapping decisions.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
single_open data argument must be PDE(inode)->data instead of NULL
otherwise seq_file->private is always NULL and we always read the
spurious data of irq 0.
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ tglx: compacted it a bit ]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
LKML-Reference: <20090828181743.GA14050@x200.localdomain>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If a parent directory (ie /proc/irq/<irq>) could not be created
we should not attempt to create subdirectories. Otherwise it
would lead that "smp_affinity" and "spurious" entries are may be
registered under /proc root instead of a proper place.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20091026202811.GD5321@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: reduce memory usage, use new cpumask API.
Replace the affinity and pending_masks with cpumask_var_t's. This adds
to the significant size reduction done with the SPARSE_IRQS changes.
The added functions (init_alloc_desc_masks & init_copy_desc_masks) are
in the include file so they can be inlined (and optimized out for the
!CONFIG_CPUMASKS_OFFSTACK case.) [Naming chosen to be consistent with
the other init*irq functions, as well as the backwards arg declaration
of "from, to" instead of the more common "to, from" standard.]
Includes a slight change to the declaration of struct irq_desc to embed
the pending_mask within ifdef(CONFIG_SMP) to be consistent with other
references, and some small changes to Xen.
Tested: sparse/non-sparse/cpumask_offstack/non-cpumask_offstack/nonuma/nosmp on x86_64
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: virtualization@lists.osdl.org
Cc: xen-devel@lists.xensource.com
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Impact: build fix on ia64
ia64's default_affinity_write() still had old cpumask_t usage:
/home/mingo/tip/kernel/irq/proc.c: In function `default_affinity_write':
/home/mingo/tip/kernel/irq/proc.c:114: error: incompatible type for argument 1 of `is_affinity_mask_valid'
make[3]: *** [kernel/irq/proc.o] Error 1
make[3]: *** Waiting for unfinished jobs....
update it to cpumask_var_t.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: Reduce stack usage, use new cpumask API. ALPHA mod!
Main change is that irq_default_affinity becomes a cpumask_var_t, so
treat it as a pointer (this effects alpha).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: change existing irq_chip API
Not much point with gentle transition here: the struct irq_chip's
setaffinity method signature needs to change.
Fortunately, not widely used code, but hits a few architectures.
Note: In irq_select_affinity() I save a temporary in by mangling
irq_desc[irq].affinity directly. Ingo, does this break anything?
(Folded in fix from KOSAKI Motohiro)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Acked-by: Ingo Molnar <mingo@redhat.com>
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: jeremy@xensource.com
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Impact: change calling convention of existing cpumask APIs
Most cpumask functions started with cpus_: these have been replaced by
cpumask_ ones which take struct cpumask pointers as expected.
These four functions don't have good replacement names; fortunately
they're rarely used, so we just change them over.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: paulus@samba.org
Cc: mingo@redhat.com
Cc: tony.luck@intel.com
Cc: ralf@linux-mips.org
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: cl@linux-foundation.org
Cc: srostedt@redhat.com
Impact: new feature
Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with
NR_CPUS set to large values. The goal is to be able to scale up to much
larger NR_IRQS value without impacting the (important) common case.
To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of
irq_desc pointers.
When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc,
this also makes the IRQ descriptors NUMA-local (to the site that calls
request_irq()).
This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now
uses desc->chip_data for x86 to store irq_cfg.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: preserve user-modified affinities on interrupts
Kumar Galak noticed that commit
1840475676 (genirq: Expose default irq
affinity mask (take 3))
overrides an already set affinity setting across a free /
request_irq(). Happens e.g. with ifdown/ifup of a network device.
Change the logic to mark the affinities as set and keep them
intact. This also fixes the unlocked access to irq_desc in
irq_select_affinity() when called from irq_affinity_proc_write()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This variable is only used in the source file, so make it static.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There are a handful of loops that go from 0 to nr_irqs and use
get_irq_desc() on them. These would allocate all the irq_desc
entries, regardless of the need for them.
Use the smarter for_each_irq_desc() iterator that will only iterate
over the present ones.
v2: make sure arch without GENERIC_HARDIRQS work too
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add CONFIG_HAVE_SPARSE_IRQ to for use condensed array.
Get rid of irq_desc[] array assumptions.
Preallocate 32 irq_desc, and irq_desc() will try to get more.
( No change in functionality is expected anywhere, except the odd build
failure where we missed a code site or where a crossing commit itroduces
new irq_desc[] usage. )
v2: according to Eric, change get_irq_desc() to irq_desc()
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
at this point nr_irqs is equal NR_IRQS
convert a few easy users from NR_IRQS to dynamic nr_irqs.
v2: according to Eric, we need to take care of arch without generic_hardirqs
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Switch /proc/irq/*/smp_affinity , /proc/irq/default_smp_affinity to
seq_files.
cat(1) reads with 1024 chunks by default, with high enough NR_CPUS, there
will be -EINVAL.
As side effect, there are now two less users of the ->read_proc interface.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current IRQ affinity interface does not provide a way to set affinity
for the IRQs that will be allocated/activated in the future.
This patch creates /proc/irq/default_smp_affinity that lets users set
default affinity mask for the newly allocated IRQs. Changing the default
does not affect affinity masks for the currently active IRQs, they
have to be changed explicitly.
Updated based on Paul J's comments and added some more documentation.
Signed-off-by: Max Krasnyansky <maxk@qualcomm.com>
Cc: pj@sgi.com
Cc: a.p.zijlstra@chello.nl
Cc: tglx@linutronix.de
Cc: rdunlap@xenotime.net
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This is useful to debug problems with interrupt handlers that return
sometimes IRQ_NONE.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Otherwise smp_affinity would only update after the next interrupt
on x86 systems.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On SN, only allow one bit to be set in the smp_affinty mask when
redirecting an interrupt. Currently setting multiple bits is allowed, but
only the first bit is used in determining the CPU to redirect to. This has
caused confusion among some customers.
[akpm@linux-foundation.org: fixes]
Signed-off-by: John Keller <jpk@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
setup_irq() releases a desc->lock before calling register_handler_proc(), so
the iteration over the IRQ action list is not protected.
(akpm: the check itself is still racy, but at least it probably won't oops
now).
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide funtions to:
- check, whether an interrupt can set the affinity
- pin the interrupt to a given cpu
Necessary for the ability to setup clocksources more flexible (e.g. use the
different HPET channels per CPU)
[akpm@osdl.org: alpha build fix]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a flag so we can prevent the irq balancing of an interrupt. Move the
bits, so we have room for more :)
Necessary for the ability to setup clocksources more flexible (e.g. use the
different HPET channels per CPU)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: pnx8550 code creates directory but resets ->nlink to 1.
create_proc_entry() et al will correctly set ->nlink for you.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While running my MCA test (hardware error injection) on 2.6.19,
I got some warning like following:
> BUG: warning at kernel/irq/migration.c:27/move_masked_irq()
>
> Call Trace:
> [<a000000100013d20>] show_stack+0x40/0xa0
> sp=e00000006b2578d0 bsp=e00000006b2510b0
> [<a000000100013db0>] dump_stack+0x30/0x60
> sp=e00000006b257aa0 bsp=e00000006b251098
> [<a0000001000de430>] move_masked_irq+0xb0/0x240
> sp=e00000006b257aa0 bsp=e00000006b251070
> [<a0000001000de6a0>] move_native_irq+0xe0/0x180
> sp=e00000006b257aa0 bsp=e00000006b251040
> [<a00000010004ff50>] iosapic_end_level_irq+0x30/0xe0
> sp=e00000006b257aa0 bsp=e00000006b251020
> [<a0000001000d94d0>] __do_IRQ+0x170/0x400
> sp=e00000006b257aa0 bsp=e00000006b250fd8
> [<a0000001000116f0>] ia64_handle_irq+0x1b0/0x260
> sp=e00000006b257aa0 bsp=e00000006b250fa8
> [<a00000010000c3a0>] ia64_leave_kernel+0x0/0x280
> sp=e00000006b257aa0 bsp=e00000006b250fa8
> [<a000000100690cf0>] _spin_unlock_irqrestore+0x30/0x60
> sp=e00000006b257c70 bsp=e00000006b250f90
It comes from:
[kernel/irq/migration.c]
26 if (CHECK_IRQ_PER_CPU(desc->status)) {
27 WARN_ON(1);
28 return;
29 }
By putting some printk in kernel, I found that irqbalance is trying to
move CPEI which is handled as PER_CPU irq. That's why.
CPEI(Corrected Platform Error Interrupt) is ia64 specific irq, is
allowed to pin to particular processor which selected by the platform, and
even it is PER_CPU but it has set_affinity handler (=iosapic_set_affinity)
as same as other IO-SAPIC-level interrupts. (I don't know why, but
I guess that there would be typical situation where the handler for
migration is needed, such as hotplug - the processor going to be
offline/hot-removed.)
To shut up this warning, there are 2 way at least:
a) fix CPEI stuff
b) prohibit setting affinity to PER_CPU irq
I'm not sure what stuff of CPEI need to be fixed, but I think that
returning error to attempting move PER_CPU irq is useful for all
applications since it will never work.
Following small patch takes b) style.
It works, the warning disappeared and irqbalance still runs well.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
