From: Christoph Lameter <cl@linux.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Paul Turner <pjt@google.com>,
Lee Schermerhorn <Lee.Schermerhorn@hp.com>,
Rik van Riel <riel@redhat.com>, Mel Gorman <mgorman@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 0/8] Announcement: Enhanced NUMA scheduling with adaptive affinity
Date: Thu, 15 Nov 2012 14:26:21 +0000 [thread overview]
Message-ID: <0000013b04769cf2-b57b16c0-5af0-4e7e-a736-e0aa2d4e4e78-000000@email.amazonses.com> (raw)
In-Reply-To: <20121113072441.GA21386@gmail.com>
On Tue, 13 Nov 2012, Ingo Molnar wrote:
> > the pages over both nodes in use.
>
> I'd not go as far as to claim that to be a general rule: the
> correct placement depends on the system and workload specifics:
> how much memory is on each node, how many tasks run on each
> node, and whether the access patterns and working set of the
> tasks is symmetric amongst each other - which is not a given at
> all.
>
> Say consider a database server that executes small and large
> queries over a large, memory-shared database, and has worker
> tasks to clients, to serve each query. Depending on the nature
> of the queries, interleaving can easily be the wrong thing to
> do.
The interleaving of memory areas that have an equal amount of shared
accesses from multiple nodes is essential to limit the traffic on the
interconnect and get top performance.
I guess through that in a non HPC environment where you are not interested
in one specific load running at top speed varying contention on the
interconnect and memory busses are acceptable. But this means that HPC
loads cannot be auto tuned.
next prev parent reply other threads:[~2012-11-15 14:26 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-12 16:04 [PATCH 0/8] Announcement: Enhanced NUMA scheduling with adaptive affinity Peter Zijlstra
2012-11-12 16:04 ` [PATCH 1/8] sched, numa, mm: Introduce sched_feat_numa() Peter Zijlstra
2012-11-12 16:04 ` [PATCH 2/8] sched, numa, mm: Implement THP migration Peter Zijlstra
2012-11-12 16:04 ` [PATCH 3/8] sched, numa, mm: Add credits for NUMA placement Peter Zijlstra
2012-11-12 16:04 ` [PATCH 4/8] sched, numa, mm: Add last_cpu to page flags Peter Zijlstra
2012-11-13 11:55 ` Ingo Molnar
2012-11-13 16:09 ` Rik van Riel
2012-11-12 16:04 ` [PATCH 5/8] sched, numa, mm: Add adaptive NUMA affinity support Peter Zijlstra
2012-11-13 0:02 ` Christoph Lameter
2012-11-13 8:19 ` Ingo Molnar
2012-11-13 22:57 ` Rik van Riel
2012-11-16 18:06 ` Rik van Riel
2012-11-16 18:14 ` Ingo Molnar
2012-11-16 18:23 ` Rik van Riel
2012-11-29 19:34 ` Andi Kleen
2012-11-12 16:04 ` [PATCH 6/8] sched, numa, mm: Implement constant, per task Working Set Sampling (WSS) rate Peter Zijlstra
2012-11-12 16:04 ` [PATCH 7/8] sched, numa, mm: Count WS scanning against present PTEs, not virtual memory ranges Peter Zijlstra
2012-11-12 16:04 ` [PATCH 8/8] sched, numa, mm: Implement slow start for working set sampling Peter Zijlstra
2012-11-12 18:48 ` Benchmark results: "Enhanced NUMA scheduling with adaptive affinity" Ingo Molnar
2012-11-15 10:08 ` Mel Gorman
2012-11-15 18:52 ` Rik van Riel
2012-11-15 21:27 ` Mel Gorman
2012-11-15 20:32 ` Linus Torvalds
2012-11-15 22:04 ` Rik van Riel
2012-11-16 14:14 ` Mel Gorman
2012-11-16 19:50 ` Andrea Arcangeli
2012-11-16 20:05 ` Mel Gorman
2012-11-16 16:16 ` Ingo Molnar
2012-11-16 15:56 ` Ingo Molnar
2012-11-16 16:25 ` Mel Gorman
2012-11-16 17:49 ` Ingo Molnar
2012-11-16 19:04 ` Mel Gorman
2012-11-12 23:43 ` [PATCH 0/8] Announcement: Enhanced NUMA scheduling with adaptive affinity Christoph Lameter
2012-11-13 7:24 ` Ingo Molnar
2012-11-15 14:26 ` Christoph Lameter [this message]
2012-11-16 15:59 ` Ingo Molnar
2012-11-16 20:57 ` Christoph Lameter
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