On Thu, Jun 22, 2017 at 10:50 AM, Andres Freund <and...@anarazel.de> wrote: > > Or, probably more robust: Simply _exit(2) without further ado, and rely > on postmaster to output an appropriate error message. Arguably it's not > actually useful to see hundreds of "WARNING: terminating connection because of > crash of another server process" messages in the log anyway. >
To support using _exit(2) in *quickdie() handlers, I would like to share another stack trace indicating self-deadlock. In this case, WAL writer process got SIGQUIT while it was already handling a SIGQUIT, leading to self-deadlock. #0 __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:95 #1 0x00007f0bf04db2bd in _int_free (av=0x7f0bf081fb20 <main_arena>, p=0x1557e60, have_lock=0) at malloc.c:3962 #2 0x00007f0bf04df53c in __GI___libc_free (mem=mem@entry=0x1557e70) at malloc.c:2968 #3 0x00007f0bf0495025 in __run_exit_handlers (status=2, listp=0x7f0bf081f5f8 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true) at exit.c:91 #4 0x00007f0bf0495045 in __GI_exit (status=<optimized out>) at exit.c:104 #5 0x0000000000843994 in wal_quickdie () #6 <signal handler called> #7 0x00007f0bf04db014 in _int_free (av=0x7f0bf081fb20 <main_arena>, p=<optimized out>, have_lock=0) at malloc.c:4014 #8 0x00007f0bf04df53c in __GI___libc_free (mem=<optimized out>) at malloc.c:2968 #9 0x00007f0bebf8b2ba in ?? () from /usr/lib/x86_64-linux-gnu/libtasn1.so.6 #10 0x00007f0bebf8c4ba in asn1_delete_structure2 () from /usr/lib/x86_64-linux-gnu/libtasn1.so.6 #11 0x00007f0beec24738 in ?? () from /usr/lib/x86_64-linux-gnu/libgnutls.so.30 #12 0x00007f0bf3bb6de7 in _dl_fini () at dl-fini.c:235 #13 0x00007f0bf0494ff8 in __run_exit_handlers (status=2, listp=0x7f0bf081f5f8 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true) at exit.c:82 #14 0x00007f0bf0495045 in __GI_exit (status=<optimized out>) at exit.c:104 #15 0x0000000000843994 in wal_quickdie () #16 <signal handler called> #17 0x00007f0bf05585b3 in __select_nocancel () at ../sysdeps/unix/syscall-template.S:84 #18 0x0000000000b7c5da in pg_usleep () #19 0x0000000000843c4a in WalWriterMain () #20 0x000000000059ac47 in AuxiliaryProcessMain ()
