On Sat, Apr 19, 2014 at 2:06 PM, Dan McGee <[email protected]> wrote:
> On Sat, Apr 19, 2014 at 1:45 PM, dormando <[email protected]> wrote: > > Any chance you could start the memcached-debug binary under gdb and then >> crash it the same way? Get a full stack trace. >> >> Thinking if I even have a 32bit host left somewhere to test with... will >> have to spin up the VM's later, but a stacktrace might be enlightening >> anyway. >> > > Program received signal SIGSEGV, Segmentation fault. > [Switching to Thread 0xf7dbfb40 (LWP 7)] > 0xf7f7f988 in __lll_unlock_elision () from /usr/lib/libpthread.so.0 > (gdb) bt > #0 0xf7f7f988 in __lll_unlock_elision () from /usr/lib/libpthread.so.0 > #1 0xf7f790e0 in __pthread_mutex_unlock_usercnt () from > /usr/lib/libpthread.so.0 > #2 0xf7f79bff in pthread_cond_wait@@GLIBC_2.3.2 () from > /usr/lib/libpthread.so.0 > #3 0x08061bfe in item_crawler_thread () > #4 0xf7f75f20 in start_thread () from /usr/lib/libpthread.so.0 > #5 0xf7ead94e in clone () from /usr/lib/libc.so.6 > > And here is a backtrace with some debug symbols, not sure what is relevant to output but I picked the obvious pthread-related variables. `bt full` shows basically nothing extra. Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0xf7dbfb40 (LWP 7)] 0xf7f7f988 in __lll_unlock_elision () from /usr/lib/libpthread.so.0 (gdb) bt #0 0xf7f7f988 in __lll_unlock_elision () from /usr/lib/libpthread.so.0 #1 0xf7f790e0 in __pthread_mutex_unlock_usercnt () from /usr/lib/libpthread.so.0 #2 0xf7f79bff in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib/libpthread.so.0 #3 0x08061bfe in item_crawler_thread (arg=0x0) at items.c:770 #4 0xf7f75f20 in start_thread () from /usr/lib/libpthread.so.0 #5 0xf7ead94e in clone () from /usr/lib/libc.so.6 (gdb) bt full #0 0xf7f7f988 in __lll_unlock_elision () from /usr/lib/libpthread.so.0 No symbol table info available. #1 0xf7f790e0 in __pthread_mutex_unlock_usercnt () from /usr/lib/libpthread.so.0 No symbol table info available. #2 0xf7f79bff in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib/libpthread.so.0 No symbol table info available. #3 0x08061bfe in item_crawler_thread (arg=0x0) at items.c:770 i = <optimized out> #4 0xf7f75f20 in start_thread () from /usr/lib/libpthread.so.0 No symbol table info available. #5 0xf7ead94e in clone () from /usr/lib/libc.so.6 No symbol table info available. (gdb) p lru_crawler_cond $1 = {__data = {__lock = 1, __futex = 0, __total_seq = 0, __wakeup_seq = 0, __woken_seq = 0, __mutex = 0x8081590 <lru_crawler_lock>, __nwaiters = 0, __broadcast_seq = 0}, __size = "\001", '\000' <repeats 31 times>, "\220\025\b\b", '\000' <repeats 11 times>, __align = 1} (gdb) p lru_crawler_lock $2 = {__data = {__lock = 0, __count = 0, __owner = 0, __kind = 256, __nusers = 0, {d = {__espins = 0, __elision = 3}, __list = {__next = 0x30000}}}, __size = '\000' <repeats 13 times>, "\001\000\000\000\000\000\000\000\000\003", __align = 0} -- --- You received this message because you are subscribed to the Google Groups "memcached" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
