Postgres Pro
Downloads
Home   >   mailing lists

Re: First set of OSDL Shared Mem scalability results, some - Mailing list pgsql-performance

From Curt Sampson
Subject Re: First set of OSDL Shared Mem scalability results, some
Date
Msg-id Pine.NEB.4.58.0410241442150.1004@angelic-vtfw.cvpn.cynic.net
Whole thread Raw
In response to Re: First set of OSDL Shared Mem scalability results, some wierdness ...  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: First set of OSDL Shared Mem scalability results, some  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
Tree view 
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

pgsql-performance by date:

Previous
From: Max Baker
Date:
Subject: Re: Vacuum takes a really long time, vacuum full required
Next
From: Tom Lane
Date:
Subject: Re: First set of OSDL Shared Mem scalability results, some