Re: First set of OSDL Shared Mem scalability results, some

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От Curt Sampson
Тема Re: First set of OSDL Shared Mem scalability results, some
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Msg-id Pine.NEB.4.58.0410241442150.1004@angelic-vtfw.cvpn.cynic.net
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Ответ на Re: First set of OSDL Shared Mem scalability results, some wierdness ...  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: First set of OSDL Shared Mem scalability results, some  (Tom Lane <tgl@sss.pgh.pa.us>)
Список 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@cynic.net>   +81 90 7737 2974   http://www.NetBSD.org
     Make up enjoying your city life...produced by BIC CAMERA

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