From: Anton Blanchard <anton@samba.org>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: mahesh@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, mingo@elte.hu,
benh@kernel.crashing.org, torvalds@linux-foundation.org
Subject: Re: [regression] 3.0-rc boot failure -- bisected to cd4ea6ae3982
Date: Fri, 15 Jul 2011 10:45:47 +1000 [thread overview]
Message-ID: <20110715104547.29c3c509@kryten> (raw)
In-Reply-To: <1310649379.2586.273.camel@twins>
Hi,
> Urgh.. so those spans are generated by sched_domain_node_span(), and
> it looks like that simply picks the 15 nearest nodes to the one we've
> got without consideration for overlap with previously generated spans.
I do wonder if we need this extra level at all on ppc64. From memory
SGI added it for their massive setups, but our largest setup is 32 nodes
and breaking that down into 16 node chunks seems overkill.
I just realised we were setting NEWIDLE on our node definition and that
was causing large amounts of rebalance work even with
SD_NODES_PER_DOMAIN=16.
After removing it and bumping SD_NODES_PER_DOMAIN to 32, things look
pretty good.
Perhaps we should allow an arch to override SD_NODES_PER_DOMAIN so this
extra level is only used by SGI boxes.
Anton
WARNING: multiple messages have this Message-ID (diff)
From: Anton Blanchard <anton@samba.org>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: mahesh@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, mingo@elte.hu,
torvalds@linux-foundation.org
Subject: Re: [regression] 3.0-rc boot failure -- bisected to cd4ea6ae3982
Date: Fri, 15 Jul 2011 10:45:47 +1000 [thread overview]
Message-ID: <20110715104547.29c3c509@kryten> (raw)
In-Reply-To: <1310649379.2586.273.camel@twins>
Hi,
> Urgh.. so those spans are generated by sched_domain_node_span(), and
> it looks like that simply picks the 15 nearest nodes to the one we've
> got without consideration for overlap with previously generated spans.
I do wonder if we need this extra level at all on ppc64. From memory
SGI added it for their massive setups, but our largest setup is 32 nodes
and breaking that down into 16 node chunks seems overkill.
I just realised we were setting NEWIDLE on our node definition and that
was causing large amounts of rebalance work even with
SD_NODES_PER_DOMAIN=16.
After removing it and bumping SD_NODES_PER_DOMAIN to 32, things look
pretty good.
Perhaps we should allow an arch to override SD_NODES_PER_DOMAIN so this
extra level is only used by SGI boxes.
Anton
next prev parent reply other threads:[~2011-07-15 0:45 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-07 10:22 [regression] 3.0-rc boot failure -- bisected to cd4ea6ae3982 Mahesh J Salgaonkar
2011-07-07 10:22 ` Mahesh J Salgaonkar
2011-07-07 10:59 ` Peter Zijlstra
2011-07-07 10:59 ` Peter Zijlstra
2011-07-07 11:55 ` Mahesh J Salgaonkar
2011-07-07 11:55 ` Mahesh J Salgaonkar
2011-07-07 12:28 ` Peter Zijlstra
2011-07-07 12:28 ` Peter Zijlstra
2011-07-14 0:34 ` Anton Blanchard
2011-07-14 0:34 ` Anton Blanchard
2011-07-14 4:35 ` Anton Blanchard
2011-07-14 4:35 ` Anton Blanchard
2011-07-14 13:16 ` Peter Zijlstra
2011-07-14 13:16 ` Peter Zijlstra
2011-07-15 0:45 ` Anton Blanchard [this message]
2011-07-15 0:45 ` Anton Blanchard
2011-07-15 8:37 ` Peter Zijlstra
2011-07-15 8:37 ` Peter Zijlstra
2011-07-18 21:35 ` Peter Zijlstra
2011-07-18 21:35 ` Peter Zijlstra
2011-07-19 4:44 ` Anton Blanchard
2011-07-19 4:44 ` Anton Blanchard
2011-07-19 10:21 ` Peter Zijlstra
2011-07-19 10:21 ` Peter Zijlstra
2011-07-20 2:03 ` Anton Blanchard
2011-07-20 2:03 ` Anton Blanchard
2011-07-20 10:14 ` Anton Blanchard
2011-07-20 10:14 ` Anton Blanchard
2011-07-20 10:45 ` Peter Zijlstra
2011-07-20 10:45 ` Peter Zijlstra
2011-07-20 12:14 ` Anton Blanchard
2011-07-20 12:14 ` Anton Blanchard
2011-07-20 14:40 ` Linus Torvalds
2011-07-20 14:40 ` Linus Torvalds
2011-07-20 14:58 ` Peter Zijlstra
2011-07-20 14:58 ` Peter Zijlstra
2011-07-20 16:04 ` Linus Torvalds
2011-07-20 16:04 ` Linus Torvalds
2011-07-20 16:42 ` Ingo Molnar
2011-07-20 16:42 ` Ingo Molnar
2011-07-20 16:42 ` Peter Zijlstra
2011-07-20 16:42 ` Peter Zijlstra
2011-07-20 17:29 ` [tip:sched/urgent] sched: Avoid creating superfluous NUMA domains on non-NUMA systems tip-bot for Peter Zijlstra
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