| From: | Curt Sampson <cjs(at)cynic(dot)net> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Kevin Brown <kevin(at)sysexperts(dot)com>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: First set of OSDL Shared Mem scalability results, some |
| Date: | 2004-10-24 05:46:16 |
| Message-ID: | Pine.NEB.4.58.0410241442150.1004@angelic-vtfw.cvpn.cynic.net |
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| Lists: | pgsql-hackers pgsql-performance |
On Sat, 23 Oct 2004, Tom Lane wrote:
> Seems to me the overhead of any such scheme would swamp the savings from
> avoiding kernel/userspace copies ...
Well, one really can't know without testing, but memory copies are
extremely expensive if they go outside of the cache.
> the locking issues alone would be painful.
I don't see why they would be any more painful than the current locking
issues. In fact, I don't see any reason to add more locking than we
already use when updating pages.
cjs
--
Curt Sampson <cjs(at)cynic(dot)net> +81 90 7737 2974 http://www.NetBSD.org
Make up enjoying your city life...produced by BIC CAMERA
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