Re: segmentation fault postgres 9.3.5 core dump perlu related ?

> On Feb 12, 2015, at 3:21 PM, Day, David <dday(at)redcom(dot)com> wrote:
>
> Update/Information sharing on my pursuit of segmentation faults
>
> FreeBSD 10.0-RELEASE-p12 amd64
> Postgres version 9.3.5
>
> Below are three postgres core files generated from two different machine ( Georgia and Alabama ) on Feb 11.
> These cores would not be caused from an environment update issue that I last suspected might be causing the segfaults
> So I am kind of back to square one in terms of thinking what is occurring.
>
> ? I am not sure that I understand the associated time events in the postgres log file output. Is this whatever happens to be running on the other postgress forked process when the cored process was detected ?
> If this is the case then I have probably been reading to much from the content of the postgres log file at the time of core.
> This probably just represents collateral damage of routine transactions that were in other forked processes at the time one of the processes cored ?
>
> Therefore I would now just assert that postgres has a sporadic segmentation problem, no known way to reliably cause it
> and am uncertain as to how to proceed to resolve it.

. . .

> Georgia-Core 8:38 - Feb 11
> [New process 101032]
> [New Thread 802c06400 (LWP 101032)]
> Core was generated by `postgres'.
> Program terminated with signal SIGSEGV, Segmentation fault.
> #0 0x000000080c4b6d51 in Perl_hfree_next_entry () from /usr/local/lib/perl5/5.18/mach/CORE/libperl.so.5.18
> (gdb) bt
> #0 0x000000080c4b6d51 in Perl_hfree_next_entry () from /usr/local/lib/perl5/5.18/mach/CORE/libperl.so.5.18
> #1 0x000000080c4cab49 in Perl_sv_clear () from /usr/local/lib/perl5/5.18/mach/CORE/libperl.so.5.18
> #2 0x000000080c4cb13a in Perl_sv_free2 () from /usr/local/lib/perl5/5.18/mach/CORE/libperl.so.5.18
> #3 0x000000080c4e5102 in Perl_free_tmps () from /usr/local/lib/perl5/5.18/mach/CORE/libperl.so.5.18
> #4 0x000000080bcfedea in plperl_destroy_interp () from /usr/local/lib/postgresql/plperl.so
> #5 0x000000080bcfec05 in plperl_fini () from /usr/local/lib/postgresql/plperl.so
> #6 0x00000000006292c6 in ?? ()
> #7 0x000000000062918d in proc_exit ()
> #8 0x00000000006443f3 in PostgresMain ()
> #9 0x00000000005ff267 in PostmasterMain ()
> #10 0x00000000005a31ba in main ()
> (gdb) info threads
> Id Target Id Frame
> * 2 Thread 802c06400 (LWP 101032) 0x000000080c4b6d51 in Perl_hfree_next_entry () from /usr/local/lib/perl5/5.18/mach/CORE/libperl.so.5.18
> * 1 Thread 802c06400 (LWP 101032) 0x000000080c4b6d51 in Perl_hfree_next_entry () from /usr/local/lib/perl5/5.18/mach/CORE/libperl.so.5.18
>

Given two of the coredumps are in down in libperl and this is FreeBSD 10.0 amd64, have you seen this?

https://rt.perl.org/Public/Bug/Display.html?id=122199 <https://rt.perl.org/Public/Bug/Display.html?id=122199>

Michael Moll suggested trying setting vm.pmap.pcid_enabled to 0 but I don’t recall seeing if that helped.

Guy