hang in jemalloc()

[Alexey Kuts]

we don't set any signal handlers,
also grepping source code of lixml2.7.6
i didn't find any sign of signal setting (except of SIGFPE in trionan.h)


24.01.2014 5:00, Jason Evans пишет:
> On Jan 21, 2014, at 2:46 AM, Alexey Kuts<akuts at yandex-team.ru>  wrote:
>> sometimes (maybe once per day) we have
>> an annoying hang in jemalloc().
>>
>> jemalloc-version: 3.4.1-0-g0135fb806e4137dc9cdf152541926a2bc95e33f0
>> Ubuntu 12.04.3 LTS, 3.2.0-33-generic x86_64 GNU/Linux
>>
>>
>> #0  0x00007f6bd681a89c in __lll_lock_wait () from /lib/x86_64-linux-gnu/libpthread.so.0
>> #1  0x00007f6bd6816080 in _L_lock_903 () from /lib/x86_64-linux-gnu/libpthread.so.0
>> #2  0x00007f6bd6815f19 in pthread_mutex_lock () from /lib/x86_64-linux-gnu/libpthread.so.0
>> #3  0x0000000000459127 in malloc_mutex_lock (mutex=0x7f6bd4400a08) at include/jemalloc/internal/mutex.h:77
>> #4  tcache_bin_flush_small (tbin=<optimized out>, binind=15, rem=3, tcache=0x7f6bd4006000) at src/tcache.c:105
>> #5  0x000000000045958d in tcache_event_hard (tcache=0x7f6bd4006000) at src/tcache.c:39
>> #6  0x0000000000437ebe in tcache_event (tcache=0x7f6bd4006000) at include/jemalloc/internal/tcache.h:271
>> #7  tcache_alloc_large (size=<optimized out>, tcache=<optimized out>, zero=<optimized out>) at include/jemalloc/internal/tcache.h:383
>> #8  arena_malloc (zero=false, size=<optimized out>, arena=0x0, try_tcache=true) at include/jemalloc/internal/arena.h:944
>> #9  imallocx (arena=0x0, try_tcache=true, size=<optimized out>) at include/jemalloc/internal/jemalloc_internal.h:798
>> #10 imalloc (size=<optimized out>) at include/jemalloc/internal/jemalloc_internal.h:807
>> #11 jemalloc (size=<optimized out>) at src/jemalloc.c:887
>> #12 0x00007f6bd6d3bad8 in xmlStrndup () from /usr/lib/x86_64-linux-gnu/libxml2.so.2
>> #13 0x00007f6bd6ce3029 in xmlNodeListGetString () from /usr/lib/x86_64-linux-gnu/libxml2.so.2
>> #14 0x00007f6bd6d0038f in xmlValidateElement () from /usr/lib/x86_64-linux-gnu/libxml2.so.2
>> #15 0x00007f6bd6d0034e in xmlValidateElement () from /usr/lib/x86_64-linux-gnu/libxml2.so.2
>> #16 0x00007f6bd6d0034e in xmlValidateElement () from /usr/lib/x86_64-linux-gnu/libxml2.so.2
>> #17 0x00007f6bd6d00528 in xmlValidateDtd () from /usr/lib/x86_64-linux-gnu/libxml2.so.2
>> #18 0x00007f6bd7005355 in xmlpp::DtdValidator::validate(xmlpp::Document const*) () from /usr/lib/libxml++-2.6.so.2
>>
>> Will appreciate any hints or suggestions
>
> I just audited the mutex operations, and I see no way that a bin mutex can enter the locked state without later being unlocked.  Is your application using the allocator inside signal handlers, by any chance?
>
> Jason

Kuts Alexey