Horton

Re: kqueue

Thomas Munro <thomas.munro@enterprisedb.com>

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From: Thomas Munro <thomas.munro@enterprisedb.com>
To: Torsten Zuehlsdorff <mailinglists@toco-domains.de>
Cc: Keith Fiske <keith@omniti.com>, Matteo Beccati <php@beccati.com>, Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, Heikki Linnakangas <hlinnaka@iki.fi>, Marko Tiikkaja <marko@joh.to>, Alvaro Herrera <alvherre@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>, Noah Misch <noah@leadboat.com>
Date: 2017-06-22T07:19:00Z
Lists: pgsql-hackers

Attachments

On Tue, Oct 11, 2016 at 8:08 PM, Torsten Zuehlsdorff
<mailinglists@toco-domains.de> wrote:
> On 28.09.2016 23:39, Thomas Munro wrote:
>> It's difficult to draw any conclusions at this point.
>
> I'm currently setting up a new FreeBSD machine. Its a FreeBSD 11 with ZFS,
> 64 GB RAM and Quad Core. If you're interested in i can give you access for
> more tests this week. Maybe this will help to draw any conclusion.

I don't plan to resubmit this patch myself, but I was doing some
spring cleaning and rebasing today and I figured it might be worth
quietly leaving a working patch here just in case anyone from the
various BSD communities is interested in taking the idea further.

Some thoughts:  We could decide to make it the default on FooBSD but
not BarBSD according to experimental results... for example several
people reported that macOS developer machines run pgbench a bit
faster.  Also, we didn't ever get to the bottom of the complaint that
NetBSD and OpenBSD systems wake up every waiting backend when anyone
calls PostmasterIsAlive[1], which this patch should in theory fix (by
using EVFILT_PROC instead of waiting on that pipe).  On the other
hand, the fix for that may be to stop calling PostmasterIsAlive in
loops[2]!

[1] https://www.postgresql.org/message-id/CAEepm%3D27K-2AP1th97kiVvKpTuria9ocbjT0cXCJqnt4if5rJQ%40mail.gmail.com
[2] https://www.postgresql.org/message-id/CAEepm%3D3FW33PeRxt0jE4N0truJqOepp72R6W-zyM5mu1bxnZRw%40mail.gmail.com

-- 
Thomas Munro
http://www.enterprisedb.com

Commits

  1. Add kqueue(2) support to the WaitEventSet API.

  2. Add WL_EXIT_ON_PM_DEATH pseudo-event.

  3. Be conservative about alignment requirements of struct epoll_event.

  4. Make idle backends exit if the postmaster dies.