| From: | "Marinos J(dot) Yannikos" <mjy(at)geizhals(dot)at> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Oleg Bartunov <oleg(at)sai(dot)msu(dot)su>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: GiST indexes and concurrency (tsearch2) |
| Date: | 2005-02-10 00:55:05 |
| Message-ID: | 420AB0E9.8070808@geizhals.at |
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| Lists: | pgsql-performance |
Tom Lane wrote:
> I'm not completely convinced that you're seeing the same thing,
> but if you're seeing a whole lot of semops then it could well be.
I'm seeing ~280 semops/second with spinlocks enabled and ~80k
semops/second (> 4 mil. for 100 queries) with --disable-spinlocks, which
increases total run time by ~20% only. In both cases, cpu usage stays
around 25%, which is a bit odd.
> [...]You said
> you're testing a quad-processor machine, so it could be that you're
> seeing the same lock contention issues that we've been trying to figure
> out for the past year ...
Are those issues specific to a particular platform (only x86/Linux?) or
is it a problem with SMP systems in general? I guess I'll be following
the current discussion on -hackers closely...
Regards,
Marinos
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