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Kernel testing triggered this warning:
| WARNING: CPU: 0 PID: 13 at kernel/sched/core.c:1156 do_set_cpus_allowed+0x7e/0x80()
| Modules linked in:
| CPU: 0 PID: 13 Comm: migration/0 Not tainted 4.2.0-rc1-00049-g25834c7 #2
| Call Trace:
| dump_stack+0x4b/0x75
| warn_slowpath_common+0x8b/0xc0
| warn_slowpath_null+0x22/0x30
| do_set_cpus_allowed+0x7e/0x80
| cpuset_cpus_allowed_fallback+0x7c/0x170
| select_fallback_rq+0x221/0x280
| migration_call+0xe3/0x250
| notifier_call_chain+0x53/0x70
| __raw_notifier_call_chain+0x1e/0x30
| cpu_notify+0x28/0x50
| take_cpu_down+0x22/0x40
| multi_cpu_stop+0xd5/0x140
| cpu_stopper_thread+0xbc/0x170
| smpboot_thread_fn+0x174/0x2f0
| kthread+0xc4/0xe0
| ret_from_kernel_thread+0x21/0x30
As Peterz pointed out:
| So the normal rules for changing task_struct::cpus_allowed are holding
| both pi_lock and rq->lock, such that holding either stabilizes the mask.
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| This is so that wakeup can happen without rq->lock and load-balance
| without pi_lock.
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| From this we already get the relaxation that we can omit acquiring
| rq->lock if the task is not on the rq, because in that case
| load-balancing will not apply to it.
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| ** these are the rules currently tested in do_set_cpus_allowed() **
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| Now, since __set_cpus_allowed_ptr() uses task_rq_lock() which
| unconditionally acquires both locks, we could get away with holding just
| rq->lock when on_rq for modification because that'd still exclude
| __set_cpus_allowed_ptr(), it would also work against
| __kthread_bind_mask() because that assumes !on_rq.
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| That said, this is all somewhat fragile.
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| Now, I don't think dropping rq->lock is quite as disastrous as it
| usually is because !cpu_active at this point, which means load-balance
| will not interfere, but that too is somewhat fragile.
|
| So we end up with a choice of two fragile..
This patch fixes it by following the rules for changing
task_struct::cpus_allowed with both pi_lock and rq->lock held.
Reported-by: kernel test robot <ying.huang@intel.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
[ Modified changelog and patch. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/BLU436-SMTP1660820490DE202E3934ED3806E0@phx.gbl
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The code ensures that when nohz full is running, at least the
boot CPU serves as a housekeeper and it can't be later offlined.
Let's assert this assumption to make sure that we have CPUs to
handle unbound jobs like workqueues and timers while nohz full
CPUs run undisturbed.
Also improve the comments on housekeeper offlining prevention.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Vatika Harlalka <vatikaharlalka@gmail.com>
Link: http://lkml.kernel.org/r/1441119060-2230-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The problem addressed in this patch is about affining unpinned
timers. Adaptive or Full Dynticks CPUs are currently disturbed
by unnecessary jitter due to firing of such timers on them.
This patch will affine timers to online CPUs which are not full
dynticks in NOHZ_FULL configured systems. It should not
introduce overhead in nohz full off case due to static keys.
Signed-off-by: Vatika Harlalka <vatikaharlalka@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1441119060-2230-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The upper limit of Tx/Rx FIFO size is 64 word by the
specification of H/W. This patch corrects to 64 word from 256 word.
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
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On Alpha we have spinlocks that are 32b in size and an efficient
cmpxchg64 implementation, so we qualify to make use of cmpxchg backed
lockrefs. Select the ARCH_USE_CMPXCHG_LOCKREF Kconfig symbol and provide
a trivial implementation of arch_spin_value_unlocked to satisfy the
lockref code.
Using Linus' simple testcase from
http://article.gmane.org/gmane.linux.file-systems/77466 on a dual CPU
ES47 system I see around an 8% gain:
N Min Max Median Avg Stddev
x 30 6194580 6295654 6272504 6272514 17694.232
+ 30 6731164 6786334 6767982 6764274 13738.863
Difference at 95.0% confidence
491760 +/- 8188.17
7.83992% +/- 0.130541%
(Student's t, pooled s = 15840.5)
Signed-off-by: Matt Turner <mattst88@gmail.com>
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drivers/regulator/mt6311-regulator.c:169:3-8: No need to set .owner here. The core will do it.
Remove .owner field if calls are used which set it automatically
Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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The driver has a I2C device id table that is used to create the modaliases
and already contains a "ltc3589" device id. So the modalias is unnecessary.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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The driver has a I2C device id table that is used to create the modaliases
and also "ad5398-regulator" is not a supported I2C id, so it's never used.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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devm_ioremap_resource() returns ERR_PTR on error.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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Commit cf736ea6f902 ("thermal: power_allocator: do not use devm*
interfaces") forgot to change a devm_kcalloc() to just kcalloc(), but
it's corresponding devm_kfree() was changed to kfree(). Allocate with
kcalloc() to match the kfree().
Fixes: cf736ea6f902 ("thermal: power_allocator: do not use devm* interfaces")
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The driver has a I2C device id table that is used to create the modaliases
and also "pfuze100-regulator" is not a supported I2C id, so is never used.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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Add backpointer to perf_env in evlist, so we can easily access env when
processing something where we have a evsel or evlist.
Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1440755289-30939-5-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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As it is not necessarily tied to a perf.data file and needs using in
places where a perf_session is not required.
Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1440755289-30939-4-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The tracing_events_path is the variable we want to change via
--debugfs-dir option, not the debugfs_mountpoint.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Raphael Beamonte <raphael.beamonte@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1440596813-12844-4-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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There's no need for find_tracing_dir, because perf already searches for
debugfs/tracefs mount on start and populate tracing_events_path.
Adding tracing_path to carry tracing dir string to be used in
get_tracing_file instead of calling find_tracing_dir.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Raphael Beamonte <raphael.beamonte@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1440596813-12844-3-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Introduce sysfs/filename__sprintf_build_id for consolidating similar
code.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20150815114259.13642.34685.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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So that functions that deal primarily with an evsel to access
information that concerns the whole evlist it is in.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1440677263-21954-5-git-send-email-kan.liang@intel.com
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-5yqtfs728r1j1u8zmg8ufxwm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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This patch creates a new script (compaction-times) to report time
spent in mm compaction. It is possible to report times in nanoseconds
(default) or microseconds (-u).
The option -p will break down results by process id, -pv will further
decompose by each compaction entry/exit.
For each compaction entry/exit what is reported is controlled by the
options:
-t report only timing
-m report migration stats
-ms report migration scanner stats
-fs report free scanner stats
The default is to report all.
Entries may be further filtered by pid, pid-range or comm (regex).
The script is useful when analysing workloads that compact memory. The
most common example will be THP allocations on systems with a lot of
uptime that has fragmented memory.
This is an example of using the script to analyse a thpscale from
mmtests which deliberately fragments memory and allocates THP in 4
separate threads
# Recording step, one of the following;
$ perf record -e 'compaction:mm_compaction_*' ./workload
# or:
$ perf script record compaction-times
# Reporting: basic
total: 2444505743ns migration: moved=357738 failed=39275
free_scanner: scanned=2705578 isolated=387875
migration_scanner: scanned=414426 isolated=397013
# Reporting: Per task stall times
$ perf script report compaction-times -- -t -p
total: 2444505743ns
6384[thpscale]: 740800017ns
6385[thpscale]: 274119512ns
6386[thpscale]: 832961337ns
6383[thpscale]: 596624877ns
# Reporting: Per-compaction attempts for task 6385
$ perf script report compaction-times -- -m -pv 6385
total: 274119512ns migration: moved=14893 failed=24285
6385[thpscale]: 274119512ns migration: moved=14893 failed=24285
6385[thpscale].1: 3033277ns migration: moved=511 failed=1
6385[thpscale].2: 9592094ns migration: moved=1524 failed=12
6385[thpscale].3: 2495587ns migration: moved=512 failed=0
6385[thpscale].4: 2561766ns migration: moved=512 failed=0
6385[thpscale].5: 2523521ns migration: moved=512 failed=0
..... output continues ...
Changes since v1:
- report stats for isolate_migratepages and isolate_freepages
(Vlastimil Babka)
- refactor code to achieve above
- add help text
- output to stdout/stderr explicitly
Signed-off-by: Tony Jones <tonyj@suse.com>
Cc: Mel Gorman <mgorman@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/1439840932-8933-1-git-send-email-tonyj@suse.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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When calling regulator_set_load, regulator_check_drms prints and returns
an error if the regulator device's flag REGULATOR_CHANGE_DRMS isn't set.
drms_uA_update, however, bails out without reporting an error.
Replace the error print with a debug level print so that we don't get
such prints when the underlying regulator doesn't support DRMS.
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
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