On 2016-08-02 11:27:25 +1200, Thomas Munro wrote: > On Tue, Aug 2, 2016 at 10:28 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > > Andres Freund <and...@anarazel.de> writes: > >> On 2016-08-01 18:09:03 -0400, Robert Haas wrote: > >>> (Also vaguely on the list of things to clean up: can't we make it so > >>> that bgworkers aren't launched from inside a signal handler? Blech.) > > > >> Isn't pretty much everything on-demand below postmaster started from a > >> signal handler? > > > > I think it depends. As an example, maybe_start_bgworker is called > > from PostmasterMain, *and* from ServerLoop, *and* from reaper, > > *and* from sigusr1_handler. That's likely excessive, but it's what > > we've got at the moment. > > I found this apparently unresolved bug report about glibc fork() > inside a signal handler deadlocking: > > https://sourceware.org/bugzilla/show_bug.cgi?id=4737 > > I wonder if that could bite postmaster. It's interesting because > comments 16 and 19 and 22 suggest that it may not be fixed.
Moreover the solution appears to be to define the problem away: http://www.opengroup.org/austin/docs/austin_445.txt https://www.opengroup.org/austin/docs/austin_446.txt -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
