lkml.org 
[lkml]   [2015]   [May]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [GIT PULL 00/30] perf/core improvements and fixes
On Mon, May 11, 2015 at 11:06:26AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Mon, May 11, 2015 at 02:09:39PM +0900, Namhyung Kim escreveu:
> > Hi Arnaldo,
> >
> > I'm seeing a segfault on 'perf report' with a large data file after
> > applying thread refcount change - it happens regardless of the atomic
> > operation.
>
> Any specific 'perf record' command line? Does it take a long time to
> reproduce? Any backtraces? I'll try to repro, its possible that we're
> doing one too many thread__put()...

It's a kernel build with '-j 20' and recorded data size is ~2.1GB.
It takes ~30 sec to reproduce.

$ perf report -i threaded/kbuild7.data --header-only
# ========
# captured on: Thu Dec 18 12:06:35 2014
# hostname : sejong
# os release : 3.17.4-1-ARCH
# perf version : 3.18.rc3.gcb4774b
# arch : x86_64
# nrcpus online : 12
# nrcpus avail : 12
# cpudesc : Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz
# cpuid : GenuineIntel,6,45,7
# total memory : 24646828 kB
# cmdline : /home/namhyung/project/linux/tools/perf/perf record -ag -o /home/namhyung/tmp/perf/threaded/kbuild7.data -- make -j20
# event : name = cycles, , size = 104, { sample_period, sample_freq } = 4000, sample_type = IP|TID|TIME|CALLCHAIN|CPU|PERIOD, disabled = 1, inherit
# HEADER_CPU_TOPOLOGY info available, use -I to display
# HEADER_NUMA_TOPOLOGY info available, use -I to display
# pmu mappings: cpu = 4, software = 1, power = 24, uncore_pcu = 13, tracepoint = 2, uncore_imc_0 = 15, uncore_imc_1 = 16, uncore_imc_2 = 17, uncore_
# ========
#


$ perf data stat -i threaded/kbuild7.data

Total event stats for 'threaded/kbuild7.data' file:

TOTAL events: 25126492
MMAP events: 114
COMM events: 117957
EXIT events: 240544
THROTTLE events: 16
UNTHROTTLE events: 16
FORK events: 120488
SAMPLE events: 23878219
MMAP2 events: 745325
FINISHED_ROUND events: 23813

Sample event stats:

20,579,564,471,104 cycles
23,878,219 samples # sampling ratio 99.745% (3989/4000)

498.736917889 second time sampled


$ perf report -i threaded/kbuild7.data
perf: Segmentation fault
-------- backtrace --------
perf[0x51c7cb]
/usr/lib/libc.so.6(+0x33540)[0x7f37eb37e540]
/usr/lib/libc.so.6(+0x9029e)[0x7f37eb3db29e]
perf[0x4dd9c8]
perf(__hists__add_entry+0x188)[0x4e2258]
perf[0x4e2580]
perf(hist_entry_iter__add+0x9d)[0x4e2a7d]
perf[0x437fda]
perf[0x4c4c8e]
perf[0x4c5176]
perf[0x4c8bab]
perf[0x4c53c2]
perf[0x4c5f0c]
perf(perf_session__process_events+0xb3)[0x4c6b23]
perf(cmd_report+0x12a0)[0x439310]
perf[0x483ec3]
perf(main+0x60a)[0x42979a]
/usr/lib/libc.so.6(__libc_start_main+0xf0)[0x7f37eb36b800]
perf(_start+0x29)[0x4298b9]
[0x0]

It seems like some memory area was corrupted..

Thanks,
Namhyung


\
 
 \ /
  Last update: 2015-05-14 11:01    [W:0.082 / U:1.072 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site