Horton

Re: Unportable implementation of background worker start

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: cm@enterprisedb.com, remi_zara@mac.com, Alvaro Herrera <alvherre@2ndquadrant.com>, pgsql-hackers@postgresql.org
Date: 2017-04-24T21:33:39Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> On 2017-04-24 13:16:44 -0700, Andres Freund wrote:
>> Unclear if related, but
>> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=gharial&dt=2017-04-24%2019%3A30%3A42
>> has a suspicious timing of failing in a weird way.

> Given that gharial is also failing on 9.6 (same set of commits) and
> coypu fails (again same set) on 9.6
> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=coypu&dt=2017-04-24%2018%3A20%3A33

coypu's problem is unrelated:

running bootstrap script ... 2017-04-24 23:04:53.084 CEST [21114] FATAL:  could not create semaphores: No space left on device
2017-04-24 23:04:53.084 CEST [21114] DETAIL:  Failed system call was semget(1, 17, 03600).

but it does seem likely that one of these patches broke gharial.
That's pretty annoying :-(

			regards, tom lane

Commits

  1. Cope with glibc too old to have epoll_create1().

  2. Make latch.c more paranoid about child-process cases.

  3. Allow multiple bgworkers to be launched per postmaster iteration.

  4. Revert "Use pselect(2) not select(2), if available, to wait in postmaster's loop."

  5. Use pselect(2) not select(2), if available, to wait in postmaster's loop.

  6. Run the postmaster's signal handlers without SA_RESTART.

  7. Fix postmaster's handling of fork failure for a bgworker process.

  8. Partially revert commit 536d47bd9d5fce8d91929bee3128fa1d08dbcc57.

  9. Avoid depending on non-POSIX behavior of fcntl(2).

  10. Remove long-obsolete catering for platforms without F_SETFD/FD_CLOEXEC.