Commit a674533078 ("tools lib traceevent: Split pevent_print_event()
into specific functionality functions") broke apart the function
pevent_print_event() into three functions.
The first function prints the comm, pid and CPU, the second prints the
timestamp.
But that commit added the printing of the CPU in the timestamp function,
which now causes pevent_print_event() to duplicate the CPU output.
Remove the redundant printing of the record's CPU from the timestamp
function.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: a674533078 ("tools lib traceevent: Split pevent_print_event() into specific functionality functions")
Link: http://lkml.kernel.org/r/20160323101628.459375d2@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The topology test case of 'perf test' seems to be broken on my x86
system - due to the comparison of a "core-id" with # of CPUs online.
There are 8 online CPUs:
$ cat /sys/devices/system/cpu/online
0-7
but core-ids are not sequential and some core-ids exceed the number
of online CPUs.
$ cat /sys/devices/system/cpu/cpu?/topology/core_id
0
1
9
10
0
1
9
10
Looks like we can safely remove the check. Output before:
$ perf --version
perf version 4.4.rc1.g34258a
$ perf test -v topo
36: Test topology in session :
--- start ---
test child forked, pid 5906
templ file: /tmp/perf-test-vCwWG3
core_id number is too big.You may need to upgrade the perf tool.
test child interrupted
---- end ----
Test topology in session: FAILED!
and after:
$ perf test -v topo
36: Test topology in session :
--- start ---
test child forked, pid 6532
templ file: /tmp/perf-test-y10wFJ
CPU 0, core 0, socket 0
CPU 1, core 1, socket 0
CPU 2, core 9, socket 0
CPU 3, core 10, socket 0
CPU 4, core 0, socket 1
CPU 5, core 1, socket 1
CPU 6, core 9, socket 1
CPU 7, core 10, socket 1
test child finished with 0
---- end ----
Test topology in session: Ok
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Link: http://lkml.kernel.org/r/20151203233219.GA27696@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
User visible changes:
- Implement 'perf stat --metric-only' (Andi Kleen)
- Fix perf script python database export crash (Chris Phlipot)
Infrastructure changes:
- perf top/report --hierarchy assorted fixes for problems introduced in this
perf/core cycle (Namhyung Kim)
- Support '~' operation in libtraceevent (Steven Rosted)
Build fixes:
- Fix bulding of jitdump on opensuse on ubuntu systems when the DWARF
devel files are not installed (Arnaldo Carvalho de Melo)
- Do not try building jitdump on unsupported arches (Jiri Olsa)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add a new mode to only print metrics. Sometimes we don't care about the
raw values, just want the computed metrics. This allows more compact
printing, so with -I each sample is only a single line. This also
allows easier plotting and processing with other tools.
The main target is with using --topdown, but it also works with -T and
standard perf stat. A few metrics are not supported.
To avoiding having to hardcode all the metrics in the code it uses a two
pass approach: first compute dummy metrics and only print the headers in
the print_metric callback. Then use the callback to print the actual
values.
There are some additional changes in the stat printout code to handle
all metrics being on a single line.
One issue is that the column code doesn't know in advance what events
are not supported by the CPU, and it would be hard to find out as this
could change based on dynamic conditions. That causes empty columns in
some cases.
The output can be fairly wide, often you may need more than 80 columns.
Example:
% perf stat -a -I 1000 --metric-only
1.001452803 frontend cycles idle insn per cycle stalled cycles per insn branch-misses of all branches
1.001452803 158.91% 0.66 2.39 2.92%
2.002192321 180.63% 0.76 2.08 2.96%
3.003088282 150.59% 0.62 2.57 2.84%
4.004369835 196.20% 0.98 1.62 3.79%
5.005227314 231.98% 0.84 1.90 4.71%
v2: Lots of updates.
v3: Use slightly narrower columns
v4: Add comment
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1457049458-28956-6-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
With all the recently added fields in the perf stat CSV output we should
finally document them in the man page. Do this here.
v2: Fix fields in documentation (Jiri)
v3: fix order of fields again (Jiri)
v4: Change order again.
v5: Document more fields (Jiri)
v6: Move time stamp first
v7: More fixes (Jiri)
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1457049458-28956-5-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The context menu in TUI hists browser checks corresponding sort keys
when creating the menu item. But hotkey actions lacks these checks so
it can filter using incorrect info.
For example, default sort key of 'perf top' doesn't contain 'comm' or
'pid' sort key so each hist entry's thread info is not reliable. Thus
it should prohibit using thread filter on 't' key.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1457533253-21419-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The commit 2eafd410e6 ("perf hists browser: Only 'Zoom into thread'
only when sort order has 'pid'") disabled thread filtering in hist
browser for the default sort key. However the he->thread is still valid
even if 'pid' sort key is not given. Only thing it should not use is
the pid (or tid) of the thread. So allow to filter by thread when
'comm' sort key is given and show pid only if 'pid' sort key is given.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1457536490-24084-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When hierarchy mode is enabled, each entry in a hierarchy level shares
the period. IOW an upper level entry's period is the sum of lower level
entries. Thus perf uses only one of them to calculate the total period
of hists. It was lowest-level (leaf) entries but it has a problem when
it comes to filters.
If a filter is applied, entries in the same level will be filtered or
not. But upper level entries still have period of their sum including
filtered one. So total sum of upper level entries will not be same as
sum of lower level entries.
This resulted in entries having more than 100% of overhead and it can be
produced using perf top with filter(s).
Reported-and-Tested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-8-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When a command-line filter is applied in hierarchy mode, output is
broken especially when filtering on lower level. The higher level
entries doesn't show up so it's hard to see the results.
Also it needs to handle multi sort keys in a single hierarchy level.
Before:
$ perf report --hierarchy -s 'cpu,{dso,comm}' --comms swapper --stdio
...
# Overhead CPU / Shared Object+Command
# ........... ...........................
#
13.79% [kernel.vmlinux] swapper
31.71% 000
13.80% [kernel.vmlinux] swapper
0.43% [e1000e] swapper
11.89% [kernel.vmlinux] swapper
9.18% [kernel.vmlinux] swapper
After:
# Overhead CPU / Shared Object+Command
# ........... ...............................
#
33.09% 003
13.79% [kernel.vmlinux] swapper
31.71% 000
13.80% [kernel.vmlinux] swapper
0.43% [e1000e] swapper
21.90% 002
11.89% [kernel.vmlinux] swapper
13.30% 001
9.18% [kernel.vmlinux] swapper
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Remove the union in evsel so that the database id and priv pointer can
be used simultainously without conflicting and crashing.
Detailed Description for the fixed bug follows:
perf script crashes with a segmentation fault on user space tool version
4.5.rc7.ge2857b when using the python database export API. It works
properly in 4.4 and prior versions.
the crash fist appeared in:
cfc8874a48 ("perf script: Process cpu/threads maps")
How to reproduce the bug:
Remove any temporary files left over from a previous crash (if you have
already attemped to reproduce the bug):
$ rm -r test_db-perf-data
$ dropdb test_db
$ perf record timeout 1 yes >/dev/null
$ perf script -s scripts/python/export-to-postgresql.py test_db
Stack Trace:
Program received signal SIGSEGV, Segmentation fault.
__GI___libc_free (mem=0x1) at malloc.c:2929
2929 malloc.c: No such file or directory.
(gdb) bt
at util/stat.c:122
argv=<optimized out>, prefix=<optimized out>) at builtin-script.c:2231
argc=argc@entry=4, argv=argv@entry=0x7fffffffdf70) at perf.c:390
at perf.c:451
Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: cfc8874a48 ("perf script: Process cpu/threads maps")
Link: http://lkml.kernel.org/r/1457500314-8912-1-git-send-email-cphlipot0@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
While building on a Docker container for ubuntu and installing package
by package one ends up with:
MKDIR /tmp/build/util/
CC /tmp/build/util/genelf.o
util/genelf.c:22:19: fatal error: dwarf.h: No such file or directory
#include <dwarf.h>
^
compilation terminated.
mv: cannot stat '/tmp/build/util/.genelf.o.tmp': No such file or directory
Because the jitdump code needs the DWARF related development packages to
be installed. So make it dependent on that so that the build can succeed
without jitdump support.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-le498robnmxd40237wej3w62@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
ignore_nmis is used in two distinct places:
1. modified through {stop,restart}_nmi by alternative_instructions
2. read by do_nmi to determine if default_do_nmi should be called or not
thus the access pattern conforms to __read_mostly and do_nmi() is a fastpath.
Signed-off-by: Kostenzer Felix <fkostenzer@live.at>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch fixes an issue with the GLOBAL_OVERFLOW_STATUS bits on
Haswell, Broadwell and Skylake processors when using PEBS.
The SDM stipulates that when the PEBS iterrupt threshold is crossed,
an interrupt is posted and the kernel is interrupted. The kernel will
find GLOBAL_OVF_SATUS bit 62 set indicating there are PEBS records to
drain. But the bits corresponding to the actual counters should NOT be
set. The kernel follows the SDM and assumes that all PEBS events are
processed in the drain_pebs() callback. The kernel then checks for
remaining overflows on any other (non-PEBS) events and processes these
in the for_each_bit_set(&status) loop.
As it turns out, under certain conditions on HSW and later processors,
on PEBS buffer interrupt, bit 62 is set but the counter bits may be
set as well. In that case, the kernel drains PEBS and generates
SAMPLES with the EXACT tag, then it processes the counter bits, and
generates normal (non-EXACT) SAMPLES.
I ran into this problem by trying to understand why on HSW sampling on
a PEBS event was sometimes returning SAMPLES without the EXACT tag.
This should not happen on user level code because HSW has the
eventing_ip which always point to the instruction that caused the
event.
The workaround in this patch simply ensures that the bits for the
counters used for PEBS events are cleared after the PEBS buffer has
been drained. With this fix 100% of the PEBS samples on my user code
report the EXACT tag.
Before:
$ perf record -e cpu/event=0xd0,umask=0x81/upp ./multichase
$ perf report -D | fgrep SAMPLES
PERF_RECORD_SAMPLE(IP, 0x2): 11775/11775: 0x406de5 period: 73469 addr: 0 exact=Y
\--- EXACT tag is missing
After:
$ perf record -e cpu/event=0xd0,umask=0x81/upp ./multichase
$ perf report -D | fgrep SAMPLES
PERF_RECORD_SAMPLE(IP, 0x4002): 11775/11775: 0x406de5 period: 73469 addr: 0 exact=Y
\--- EXACT tag is set
The problem tends to appear more often when multiple PEBS events are used.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: namhyung@kernel.org
Link: http://lkml.kernel.org/r/1457034642-21837-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch tries to fix a PEBS warning found in my stress test. The
following perf command can easily trigger the pebs warning or spurious
NMI error on Skylake/Broadwell/Haswell platforms:
sudo perf record -e 'cpu/umask=0x04,event=0xc4/pp,cycles,branches,ref-cycles,cache-misses,cache-references' --call-graph fp -b -c1000 -a
Also the NMI watchdog must be enabled.
For this case, the events number is larger than counter number. So
perf has to do multiplexing.
In perf_mux_hrtimer_handler, it does perf_pmu_disable(), schedule out
old events, rotate_ctx, schedule in new events and finally
perf_pmu_enable().
If the old events include precise event, the MSR_IA32_PEBS_ENABLE
should be cleared when perf_pmu_disable(). The MSR_IA32_PEBS_ENABLE
should keep 0 until the perf_pmu_enable() is called and the new event is
precise event.
However, there is a corner case which could restore PEBS_ENABLE to
stale value during the above period. In perf_pmu_disable(), GLOBAL_CTRL
will be set to 0 to stop overflow and followed PMI. But there may be
pending PMI from an earlier overflow, which cannot be stopped. So even
GLOBAL_CTRL is cleared, the kernel still be possible to get PMI. At
the end of the PMI handler, __intel_pmu_enable_all() will be called,
which will restore the stale values if old events haven't scheduled
out.
Once the stale pebs value is set, it's impossible to be corrected if
the new events are non-precise. Because the pebs_enabled will be set
to 0. x86_pmu.enable_all() will ignore the MSR_IA32_PEBS_ENABLE
setting. As a result, the following NMI with stale PEBS_ENABLE
trigger pebs warning.
The pending PMI after enabled=0 will become harmless if the NMI handler
does not change the state. This patch checks cpuc->enabled in pmi and
only restore the state when PMU is active.
Here is the dump:
Call Trace:
<NMI> [<ffffffff813c3a2e>] dump_stack+0x63/0x85
[<ffffffff810a46f2>] warn_slowpath_common+0x82/0xc0
[<ffffffff810a483a>] warn_slowpath_null+0x1a/0x20
[<ffffffff8100fe2e>] intel_pmu_drain_pebs_nhm+0x2be/0x320
[<ffffffff8100caa9>] intel_pmu_handle_irq+0x279/0x460
[<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
[<ffffffff811f290d>] ? vunmap_page_range+0x20d/0x330
[<ffffffff811f2f11>] ? unmap_kernel_range_noflush+0x11/0x20
[<ffffffff8148379f>] ? ghes_copy_tofrom_phys+0x10f/0x2a0
[<ffffffff814839c8>] ? ghes_read_estatus+0x98/0x170
[<ffffffff81005a7d>] perf_event_nmi_handler+0x2d/0x50
[<ffffffff810310b9>] nmi_handle+0x69/0x120
[<ffffffff810316f6>] default_do_nmi+0xe6/0x100
[<ffffffff810317f2>] do_nmi+0xe2/0x130
[<ffffffff817aea71>] end_repeat_nmi+0x1a/0x1e
[<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
[<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
[<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
<<EOE>> <IRQ> [<ffffffff81006df8>] ? x86_perf_event_set_period+0xd8/0x180
[<ffffffff81006eec>] x86_pmu_start+0x4c/0x100
[<ffffffff8100722d>] x86_pmu_enable+0x28d/0x300
[<ffffffff811994d7>] perf_pmu_enable.part.81+0x7/0x10
[<ffffffff8119cb70>] perf_mux_hrtimer_handler+0x200/0x280
[<ffffffff8119c970>] ? __perf_install_in_context+0xc0/0xc0
[<ffffffff8110f92d>] __hrtimer_run_queues+0xfd/0x280
[<ffffffff811100d8>] hrtimer_interrupt+0xa8/0x190
[<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0
[<ffffffff81051bd8>] local_apic_timer_interrupt+0x38/0x60
[<ffffffff817af01d>] smp_apic_timer_interrupt+0x3d/0x50
[<ffffffff817ad15c>] apic_timer_interrupt+0x8c/0xa0
<EOI> [<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0
[<ffffffff81123de5>] ? smp_call_function_single+0xd5/0x130
[<ffffffff81123ddb>] ? smp_call_function_single+0xcb/0x130
[<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0
[<ffffffff8119765a>] event_function_call+0x10a/0x120
[<ffffffff8119c660>] ? ctx_resched+0x90/0x90
[<ffffffff811971e0>] ? cpu_clock_event_read+0x30/0x30
[<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60
[<ffffffff8119772b>] _perf_event_enable+0x5b/0x70
[<ffffffff81197388>] perf_event_for_each_child+0x38/0xa0
[<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60
[<ffffffff811a0ffd>] perf_ioctl+0x12d/0x3c0
[<ffffffff8134d855>] ? selinux_file_ioctl+0x95/0x1e0
[<ffffffff8124a3a1>] do_vfs_ioctl+0xa1/0x5a0
[<ffffffff81036d29>] ? sched_clock+0x9/0x10
[<ffffffff8124a919>] SyS_ioctl+0x79/0x90
[<ffffffff817ac4b2>] entry_SYSCALL_64_fastpath+0x1a/0xa4
---[ end trace aef202839fe9a71d ]---
Uhhuh. NMI received for unknown reason 2d on CPU 2.
Do you have a strange power saving mode enabled?
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1457046448-6184-1-git-send-email-kan.liang@intel.com
[ Fixed various typos and other small details. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge perf/core improvements and fixes from Arnaldo Carvalho de Melo:
User visible changes:
- Allow grouping multiple sort keys per 'perf report/top --hierarchy'
level (Namhyung Kim)
- Document 'perf stat --detailed' option (Borislav Petkov)
Infrastructure changes:
- jitdump prep work for supporting it with Intel PT (Adrian Hunter)
- Use 64-bit shifts with (TSC) time conversion (Adrian Hunter)
Fixes:
- Explicitly declare inc_group_count as a void function (Colin Ian King)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now hpp formats are linked using perf_hpp_list_node when hierarchy is
enabled. Use this info to print entries with multiple sort keys in a
single hierarchy properly.
For example, the below example shows using 4 sort keys with 2 levels.
$ perf report --hierarchy -s '{prev_pid,prev_comm},{next_pid,next_comm}' \
--percent-limit 1 -i perf.data.sched
...
# Overhead prev_pid+prev_comm / next_pid+next_comm
# ........... .......................................
#
22.36% 0 swapper/0
9.48% 17773 transmission-gt
5.25% 109 kworker/0:1H
1.53% 6524 Xephyr
21.39% 17773 transmission-gt
9.52% 0 swapper/0
9.04% 0 swapper/2
1.78% 0 swapper/3
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457361308-514-6-git-send-email-namhyung@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
