Re: 7.3.8 under FC3 takes excessive semaphores?

Mark Cave-Ayland wrote:
>
> > -----Original Message-----
> > From: Tom Lane [mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us]
> > Sent: 31 January 2005 16:35
> > To: Mark Cave-Ayland
> > Cc: pgsql-hackers(at)postgresql(dot)org
> > Subject: Re: [HACKERS] 7.3.8 under FC3 takes excessive semaphores?
>
> (cut)
>
> > Judging by the symptoms, you have built a version with what
> > we now call --disable-spinlocks; that is, it didn't figure
> > out how to do assembly TAS on your platform and fell back to
> > using SysV semaphores for spinlocks. Quite aside from the
> > drain on semaphores, the performance is going to be
> > spectacularly bad, so you'd better fix that.
> >
> > regards, tom lane
>
>
> Hi Tom,
>
> I'd just about managed to come to the same conclusion before your email
> arrived by spending the afternoon with gdb tracing into the LWLock code :)
>
> I've just installed 7.4.6 on the same box and this time the spinlocks are
> correctly picked up and everything works as expected. I think rather than
> fixing the 7.3.x source, we'll take the plunge and plan for a complete dump
> and restore of the database cluster over a weekend.

And with 7.4 and later we will throw a configure error if we don't find
native spinlocks so you will have no surprises in the future.

--
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