Horton

Re: RE: [COMMITTERS] pgsql/src/backend/access/transam ( xact.c xlog.c)

Bruce Momjian <pgman@candle.pha.pa.us>

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From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Alfred Perlstein <bright@wintelcom.net>
Cc: Don Baccus <dhogaza@pacifier.com>, Vadim Mikheev <vmikheev@sectorbase.com>, "'Tom Lane'" <tgl@sss.pgh.pa.us>, Tatsuo Ishii <t-ishii@sra.co.jp>, peter_e@gmx.net, pgsql-hackers@postgresql.org
Date: 2000-11-16T20:11:50Z
Lists: pgsql-hackers 
> > In OS kernel design, you try to avoid process herding bottlenecks. 
> > Here, we want them herded, and giving up the CPU may be the best way to
> > do it.
> 
> Yes, but if everyone yeilds you're back where you started, and with
> 128 or more backends do you really want to cause possibly that many
> context switches per fsync?

You are going to kernel call/yield anyway to fsync, so why not try and
if someone does the fsync, we don't need to do it.  I am suggesting
re-checking the need for fsync after the return from sleep(0).

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