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

> * Don Baccus <dhogaza@pacifier.com> [001116 13:46]:
> > At 02:13 PM 11/16/00 -0500, Bruce Momjian wrote:
> > 
> > >> I think the default should probably be no delay, and the documentation
> > >> on enabling this needs to be clear and obvious (i.e. hard to miss).
> > >
> > >I just talked to Tom Lane about this.  I think a sleep(0) just before
> > >the flush would be the best.  It would reliquish the cpu slice if
> > >another process is ready to run.  If no other backend is running, it
> > >probably just returns.  If there is another one, it gives it a chance to
> > >complete.  On return from sleep(0), it can check if it still needs to
> > >flush.  This would tend to bunch up flushers so they flush only once,
> > >while not delaying cases where only one backend is running.
> > 
> > This sounds like an interesting approach, yes.
> Question: Is sleep(0) guaranteed to at least give up control? 
> 
> The way I read my UnixWare 7's man page, it might not, since alarm(0)
> just cancels the alarm...

Well, it certainly is a kernel call, and most OS's re-evaluate on kernel
call return.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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