| Age | Commit message (Collapse) | Author |
|---|
|
[root@zoo ~]# perf trace -a -e lseek | head -1
546.922 ( 0.004 ms): 1184 lseek(fd: 26, offset: 0, whence: CUR) = 2
[root@zoo ~]#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2eiuhwz9jbnhj80q6jaqeji4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
A valid parent pointer is always going to have a non-zero reference
count, but if we look up the parent optimistically without locking, we
have to protect against the (very unlikely) race against renaming
changing the parent from under us.
We do that by using lockref_get_not_zero(), and then re-checking the
parent pointer after getting a valid reference.
[ This is a re-implementation of a chunk from the original patch by
Waiman Long: "dcache: Enable lockless update of dentry's refcount".
I've completely rewritten the patch-series and split it up, but I'm
attributing this part to Waiman as it's close enough to his earlier
patch - Linus ]
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This behaves like "lockref_get_not_zero()", but instead of doing nothing
if the count was zero, it returns with the lock held.
This allows callers to revalidate the lockref-protected data structure
if required even if the count was zero to begin with, and possibly
increment the count if it passes muster.
In particular, the dentry code wants this when it wants to turn an
RCU-protected dentry into a stable refcounted one: if the dentry count
it zero, but the sequence number still validates the dentry, we can take
a reference to it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
For some dsos (e.g., libc, libpthread, kernel modules) the symbol offset
is huge. e.g.,
qemu-kvm 17238/17242 [007] 762235.640311:
ffffffff816288a1 __schedule+0x451 ([kernel.kallsyms])
ffffffff81629609 schedule+0x29 ([kernel.kallsyms])
ffffffffa00a6ded kvm_vcpu_block+0xffffffffa00a106d (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
ffffffffa00bae6b kvm_arch_vcpu_ioctl_run+0xffffffffa00a118b (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
ffffffffa00a4d7a kvm_vcpu_ioctl+0xffffffffa00a141a (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
ffffffff811a7bdb do_vfs_ioctl+0x8b ([kernel.kallsyms])
ffffffff811a80c1 sys_ioctl+0x91 ([kernel.kallsyms])
ffffffff81633182 system_call+0x72 ([kernel.kallsyms])
7f882a97af27 __GI___ioctl+0x7f882a891007 (/lib64/libc-2.14.90.so)
100000002 [unknown] ([unknown])
It seems to be maps with a non-0 start. Taking that into account the
offsets are correct:
qemu-kvm 17238/17242 [007] 762235.640311:
ffffffff816288a1 __schedule+0x451 ([kernel.kallsyms])
ffffffff81629609 schedule+0x29 ([kernel.kallsyms])
ffffffffa00a6ded kvm_vcpu_block+0x6d (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
ffffffffa00bae6b kvm_arch_vcpu_ioctl_run+0x18b (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
ffffffffa00a4d7a kvm_vcpu_ioctl+0x41a (/lib/modules/3.11.0-rc1+/kernel/arch/x86/kvm/kvm.ko)
ffffffff811a7bdb do_vfs_ioctl+0x8b ([kernel.kallsyms])
ffffffff811a80c1 sys_ioctl+0x91 ([kernel.kallsyms])
ffffffff81633182 system_call+0x72 ([kernel.kallsyms])
7f882a97af27 __GI___ioctl+0x7 (/lib64/libc-2.14.90.so)
100000002 [unknown] ([unknown])
Signed-off-by: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/1375026512-45826-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
Some hardware events might not be supported on a system. Listing those
events seems meaningless and confusing to users. Let's skip them.
Before:
$ perf list cache | wc -l
33
After:
$ perf list cache | wc -l
27
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1377571313-14722-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
Add a test for the newly added PERF_COUNT_SW_DUMMY event. The test
checks that tracking events continue when an event is disabled but a
dummy software event is not disabled.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1377975053-3811-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
Add support for the new dummy software event PERF_COUNT_SW_DUMMY.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1377975053-3811-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
When an event is disabled the "tracking" events selected by the 'mmap',
'comm' and 'task' bits of struct perf_event_attr, are also disabled.
However, the information those events provide is necessary to resolve
symbols for when the main event is re-enabled.
The "tracking" events can be kept enabled by putting them on another
event, but that requires an event that otherwise does nothing. A new
software event PERF_COUNT_SW_DUMMY is added for that purpose.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1377975053-3811-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
That uses the arg mask mechanism just introduced to suppress ignored
arguments according to the futex operation.
Based on an initial patch from David Ahern that showed the need for some
way to allow args to tell how many further args should be shown.
Initial-patch-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-0k30it46r4hv5eanefbdmj5t@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
The futex syscall ignores some arguments according to the 'operation'
arg, so allow arg formatters to mask those.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-abqrg3oldgfsdnltfrvso9f7@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fix from James Bottomley:
"This is a bug fix for the pm80xx driver. It turns out that when the
new hardware support was added in 3.10 the IO command size was kept at
the old hard coded value. This means that the driver attaches to some
new cards and then simply hangs the system"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
[SCSI] pm80xx: fix Adaptec 71605H hang
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot fix from Peter Anvin:
"A single very small boot fix for very large memory systems (> 0.5T)"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Fix boot crash with DEBUG_PAGE_ALLOC=y and more than 512G RAM
|
|
Pull slave-dma fix from Vinod Koul:
"A fix for resolving TI_EDMA driver's build error in allmodconfig to
have filter function built in""
* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
dma/Kconfig: TI_EDMA needs to be boolean
|
|
Use the convenience function instead of __GFP_ZERO.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/f58599ae1a8d7b32d37e9cf283e95fba6452f7f6.1377809875.git.joe@perches.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
If PERF_SAMPLE_BRANCH_STACK is enabled then samples are returned
with the format { u64 from, to, flags } but the flags layout
is not specified.
This field has the type struct perf_branch_entry; move this
definition into include/uapi/linux/perf_event.h so users can
access these fields.
This is similar to the existing inclusion of perf_mem_data_src in
the include/uapi/linux/perf_event.h file.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1308231544420.1889@vincent-weaver-1.um.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Adds a new PERF_RECORD_MMAP2 record type which is essence
an expanded version of PERF_RECORD_MMAP.
Used to request mmap records with more information about
the mapping, including device major, minor and the inode
number and generation for mappings associated with files
or shared memory segments. Works for code and data
(with attr->mmap_data set).
Existing PERF_RECORD_MMAP record is unmodified by this patch.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: http://lkml.kernel.org/r/1377079825-19057-2-git-send-email-eranian@google.com
[ Added Al to the Cc:. Are the ino, maj/min exports of vma->vm_file OK? ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Compared to old atom, Silvermont has offcore and has more events
that support PEBS.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1374138144-17278-2-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Silvermont (22nm Atom) has two offcore response configuration MSRs,
unlike other Intel CPU, its event code for MSR_OFFCORE_RSP_1 is 0x02b7.
To avoid complicating intel_fixup_er(), use INTEL_UEVENT_EXTRA_REG to
define MSR_OFFCORE_RSP_X. So intel_fixup_er() can find the event code
for OFFCORE_RSP_N by x86_pmu.extra_regs[N].event.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1374138144-17278-1-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
I found that on my WSM box I had a redundant domain:
[ 0.949769] CPU0 attaching sched-domain:
[ 0.953765] domain 0: span 0,12 level SIBLING
[ 0.958335] groups: 0 (cpu_power = 587) 12 (cpu_power = 588)
[ 0.964548] domain 1: span 0-5,12-17 level MC
[ 0.969206] groups: 0,12 (cpu_power = 1175) 1,13 (cpu_power = 1176) 2,14 (cpu_power = 1176) 3,15 (cpu_power = 1176) 4,16 (cpu_power = 1176) 5,17 (cpu_power = 1176)
[ 0.984993] domain 2: span 0-5,12-17 level CPU
[ 0.989822] groups: 0-5,12-17 (cpu_power = 7055)
[ 0.995049] domain 3: span 0-23 level NUMA
[ 0.999620] groups: 0-5,12-17 (cpu_power = 7055) 6-11,18-23 (cpu_power = 7056)
Note how domain 2 has only a single group and spans the same CPUs as
domain 1. We should not keep such domains and do in fact have code to
prune these.
It turns out that the 'new' SD_PREFER_SIBLING flag causes this, it
makes sd_parent_degenerate() fail on the CPU domain. We can easily
fix this by 'ignoring' the SD_PREFER_SIBLING bit and transfering it
to whatever domain ends up covering the span.
With this patch the domains now look like this:
[ 0.950419] CPU0 attaching sched-domain:
[ 0.954454] domain 0: span 0,12 level SIBLING
[ 0.959039] groups: 0 (cpu_power = 587) 12 (cpu_power = 588)
[ 0.965271] domain 1: span 0-5,12-17 level MC
[ 0.969936] groups: 0,12 (cpu_power = 1175) 1,13 (cpu_power = 1176) 2,14 (cpu_power = 1176) 3,15 (cpu_power = 1176) 4,16 (cpu_power = 1176) 5,17 (cpu_power = 1176)
[ 0.985737] domain 2: span 0-23 level NUMA
[ 0.990231] groups: 0-5,12-17 (cpu_power = 7055) 6-11,18-23 (cpu_power = 7056)
Reviewed-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-ys201g4jwukj0h8xcamakxq1@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Rik reported some weirdness due to the group_imb code. As a start to
looking at it, clean it up a little and add a few explanatory
comments.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-caeeqttnla4wrrmhp5uf89gp@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Use for_each_cpu_and() and thereby avoid computing the capacity for
CPUs we know we're not interested in.
Reviewed-by: Paul Turner <pjt@google.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-lppceyv6kb3a19g8spmrn20b@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
For easier access, less dereferences and more consistent value, store
the group power in update_sg_lb_stats() and use it thereafter. The
actual value in sched_group::sched_group_power::power can change
throughout the load-balance pass if we're unlucky.
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-739xxqkyvftrhnh9ncudutc7@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Since we already compute (but don't store) the sgs load_per_task value
in update_sg_lb_stats() we might as well store it and not re-compute
it later on.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-ym1vmljiwbzgdnnrwp9azftq@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
We can shrink sg_lb_stats because rq::nr_running is an unsigned int
and cpu numbers are 'int'
Before:
sgs: /* size: 72, cachelines: 2, members: 10 */
sds: /* size: 184, cachelines: 3, members: 7 */
After:
sgs: /* size: 56, cachelines: 1, members: 10 */
sds: /* size: 152, cachelines: 3, members: 7 */
Further we can avoid clearing all of sds since we do a total
clear/assignment of sg_stats in update_sg_lb_stats() with exception of
busiest_stat.avg_load which is referenced in update_sd_pick_busiest().
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-0klzmz9okll8wc0nsudguc9p@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
There is no reason to maintain separate variables for this_group
and busiest_group in sd_lb_stat, except saving some space.
But this structure is always allocated in stack, so this saving
isn't really benificial [peterz: reducing stack space is good; in this
case readability increases enough that I think its still beneficial]
This patch unify these variables, so IMO, readability may be improved.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
[ Rename this to local -- avoids confusion between this_cpu and the C++ this pointer. ]
Reviewed-by: Paul Turner <pjt@google.com>
[ Lots of style edits, a few fixes and a rename. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1375778203-31343-4-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Now checking whether this cpu is appropriate to balance or not
is embedded into update_sg_lb_stats() and this checking has no direct
relationship to this function. There is not enough reason to place
this checking at update_sg_lb_stats(), except saving one iteration
for sched_group_cpus.
In this patch, I factor out this checking to should_we_balance() function.
And before doing actual work for load_balancing, check whether this cpu is
appropriate to balance via should_we_balance(). If this cpu is not
a candidate for balancing, it quit the work immediately.
With this change, we can save two memset cost and can expect better
compiler optimization.
Below is result of this patch.
* Vanilla *
text data bss dec hex filename
34499 1136 116 35751 8ba7 kernel/sched/fair.o
* Patched *
text data bss dec hex filename
34243 1136 116 35495 8aa7 kernel/sched/fair.o
In addition, rename @balance to @continue_balancing in order to represent
its purpose more clearly.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
[ s/should_balance/continue_balancing/g ]
Reviewed-by: Paul Turner <pjt@google.com>
[ Made style changes and a fix in should_we_balance(). ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1375778203-31343-3-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Remove one division operation in find_busiest_queue() by using
crosswise multiplication:
wl_i / power_i > wl_j / power_j :=
wl_i * power_j > wl_j * power_i
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
[ Expanded the changelog. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1375778203-31343-2-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The current throttling code triggers WARN below via following
workload (only hit on AMD machine with 48 CPUs):
# while [ 1 ]; do perf record perf bench sched messaging; done
WARNING: at arch/x86/kernel/cpu/perf_event.c:1054 x86_pmu_start+0xc6/0x100()
SNIP
Call Trace:
<IRQ> [<ffffffff815f62d6>] dump_stack+0x19/0x1b
[<ffffffff8105f531>] warn_slowpath_common+0x61/0x80
[<ffffffff8105f60a>] warn_slowpath_null+0x1a/0x20
[<ffffffff810213a6>] x86_pmu_start+0xc6/0x100
[<ffffffff81129dd2>] perf_adjust_freq_unthr_context.part.75+0x182/0x1a0
[<ffffffff8112a058>] perf_event_task_tick+0xc8/0xf0
[<ffffffff81093221>] scheduler_tick+0xd1/0x140
[<ffffffff81070176>] update_process_times+0x66/0x80
[<ffffffff810b9565>] tick_sched_handle.isra.15+0x25/0x60
[<ffffffff810b95e1>] tick_sched_timer+0x41/0x60
[<ffffffff81087c24>] __run_hrtimer+0x74/0x1d0
[<ffffffff810b95a0>] ? tick_sched_handle.isra.15+0x60/0x60
[<ffffffff81088407>] hrtimer_interrupt+0xf7/0x240
[<ffffffff81606829>] smp_apic_timer_interrupt+0x69/0x9c
[<ffffffff8160569d>] apic_timer_interrupt+0x6d/0x80
<EOI> [<ffffffff81129f74>] ? __perf_event_task_sched_in+0x184/0x1a0
[<ffffffff814dd937>] ? kfree_skbmem+0x37/0x90
[<ffffffff815f2c47>] ? __slab_free+0x1ac/0x30f
[<ffffffff8118143d>] ? kfree+0xfd/0x130
[<ffffffff81181622>] kmem_cache_free+0x1b2/0x1d0
[<ffffffff814dd937>] kfree_skbmem+0x37/0x90
[<ffffffff814e03c4>] consume_skb+0x34/0x80
[<ffffffff8158b057>] unix_stream_recvmsg+0x4e7/0x820
[<ffffffff814d5546>] sock_aio_read.part.7+0x116/0x130
[<ffffffff8112c10c>] ? __perf_sw_event+0x19c/0x1e0
[<ffffffff814d5581>] sock_aio_read+0x21/0x30
[<ffffffff8119a5d0>] do_sync_read+0x80/0xb0
[<ffffffff8119ac85>] vfs_read+0x145/0x170
[<ffffffff8119b699>] SyS_read+0x49/0xa0
[<ffffffff810df516>] ? __audit_syscall_exit+0x1f6/0x2a0
[<ffffffff81604a19>] system_call_fastpath+0x16/0x1b
---[ end trace 622b7e226c4a766a ]---
The reason is a race in perf_event_task_tick() throttling code.
The race flow (simplified code):
- perf_throttled_count is per cpu variable and is
CPU throttling flag, here starting with 0
- perf_throttled_seq is sequence/domain for allowed
count of interrupts within the tick, gets increased
each tick
on single CPU (CPU bounded event):
... workload
perf_event_task_tick:
|
| T0 inc(perf_throttled_seq)
| T1 needs_unthr = xchg(perf_throttled_count, 0) == 0
tick gets interrupted:
... event gets throttled under new seq ...
T2 last NMI comes, event is throttled - inc(perf_throttled_count)
back to tick:
| perf_adjust_freq_unthr_context:
|
| T3 unthrottling is skiped for event (needs_unthr == 0)
| T4 event is stop and started via freq adjustment
|
tick ends
... workload
... no sample is hit for event ...
perf_event_task_tick:
|
| T5 needs_unthr = xchg(perf_throttled_count, 0) != 0 (from T2)
| T6 unthrottling is done on event (interrupts == MAX_INTERRUPTS)
| event is already started (from T4) -> WARN
Fixing this by not checking needs_unthr again and thus
check all events for unthrottling.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Reported-by: Jan Stancek <jstancek@redhat.com>
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1377355554-8934-1-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
For performance reasons, when SMAP is in use, SMAP is left open for an
entire put_user_try { ... } put_user_catch(); block, however, calling
__put_user() in the middle of that block will close SMAP as the
STAC..CLAC constructs intentionally do not nest.
Furthermore, using __put_user() rather than put_user_ex() here is bad
for performance.
Thus, introduce new [compat_]save_altstack_ex() helpers that replace
__[compat_]save_altstack() for x86, being currently the only
architecture which supports put_user_try { ... } put_user_catch().
Reported-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.8+
Link: http://lkml.kernel.org/n/tip-es5p6y64if71k8p5u08agv9n@git.kernel.org
|
|
Add SMAP annotations to csum_partial_copy_to/from_user(). These
functions legitimately access user space and thus need to set the AC
flag.
TODO: add explicit checks that the side with the kernel space pointer
really points into kernel space.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-2aps0u00eer658fd5xyanan7@git.kernel.org
Cc: <stable@vger.kernel.org> # v3.7+
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
