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From: "Martin J. Bligh" <mbligh@aracnet.com>
To: brettspamacct@fastclick.com
Cc: linux-kernel mailing list <linux-kernel@vger.kernel.org>,
	jbarnes@engr.sgi.com
Subject: Re: How can I optimize a process on a NUMA architecture(x86-64 specifically)?
Date: Fri, 21 May 2004 11:30:51 -0700	[thread overview]
Message-ID: <79400000.1085164250@flay> (raw)
In-Reply-To: <40AE46F9.60600@fastclick.com>

> So could process 0 run on processor 0, allocating local to processor 0, then run on processor 1, allocating local to processor 1, this way allocating to both processors?  So over time process 0's allocations would be split up between both processors, defeating NUMA.  The homenode concept + explicit CPU pinning seems useful in that they allow you to take advantage of NUMA better. Without these two things the kernel will just allocate on the currently running CPU whatever that may be when in fact a preference must be given to a CPU at some point, hopefully early on in the life of the process, in order to take advantage of NUMA.


For any given situation, you can come up with a scheduler mod that improves
things. The problem is making something generic that works well in most
cases. 

I suggest: (1) read the archives. (2) Try implementing it if you still 
don't beleive me ;-) The main problem with the homenode scheduler is that
you're more likely to end up in a situation where you're running "off-node"
and allocating stuff back from your "home-node". This stuff isn't 
deterministic.

M.




  reply	other threads:[~2004-05-21 18:31 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-05-21  0:51 Brett E.
2004-05-21  1:29 ` Jesse Barnes
2004-05-21  6:37 ` Martin J. Bligh
2004-05-21 17:27   ` Brett E.
2004-05-21 17:46     ` Martin J. Bligh
2004-05-21 18:14       ` Brett E.
2004-05-21 18:30         ` Martin J. Bligh [this message]
2004-05-21 18:58         ` Jesse Barnes
2004-05-21 19:08           ` Martin J. Bligh
2004-05-23  2:49     ` David Schwartz
     [not found] <1Y6yr-eM-11@gated-at.bofh.it>
     [not found] ` <1YbRm-4iF-11@gated-at.bofh.it>
     [not found]   ` <1Yma3-4cF-3@gated-at.bofh.it>
     [not found]     ` <1YmjP-4jX-37@gated-at.bofh.it>
2004-05-21 19:17       ` Andi Kleen
     [not found]       ` <1YmMN-4Kh-17@gated-at.bofh.it>
     [not found]         ` <1Yn67-50q-7@gated-at.bofh.it>
2004-05-21 19:19           ` Andi Kleen
2004-05-21 20:32             ` Martin J. Bligh
2004-05-21 23:42               ` Brett E.
2004-05-22  6:13                 ` Martin J. Bligh
2004-05-22  7:41                   ` Andi Kleen
2004-05-23  0:28                 ` Bryan O'Sullivan
2004-05-23 14:28                   ` Andi Kleen
2004-05-24 22:00                     ` Andrew Theurer
2004-05-25  0:27                       ` Scott Robert Ladd
2004-05-25  1:09                       ` Brett E.
     [not found]     ` <1YRnC-3vk-5@gated-at.bofh.it>
2004-05-23 11:57       ` Andi Kleen

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