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From: Peter Zijlstra <peterz@infradead.org>
To: venkatesh.pallipadi@intel.com
Cc: Gautham R Shenoy <ego@in.ibm.com>,
	Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
	Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
	Arjan van de Ven <arjan@infradead.org>,
	linux-kernel@vger.kernel.org,
	Suresh Siddha <suresh.b.siddha@intel.com>
Subject: Re: [patch 2/2] sched: Scale the nohz_tracker logic by making it per NUMA node
Date: Mon, 14 Dec 2009 23:21:23 +0100	[thread overview]
Message-ID: <1260829283.8023.124.camel@laptop> (raw)
In-Reply-To: <20091211013056.450920000@intel.com>

On Thu, 2009-12-10 at 17:27 -0800, venkatesh.pallipadi@intel.com wrote:
> Having one idle CPU doing the rebalancing for all the idle CPUs in
> nohz mode does not scale well with increasing number of cores and
> sockets. Make the nohz_tracker per NUMA node. This results in multiple
> idle load balancing happening at NUMA node level and idle load balancer
> only does the rebalance domain among all the other nohz CPUs in that
> NUMA node.
> 
> This addresses the below problem with the current nohz ilb logic
> * The lone balancer may end up spending a lot of time doing the
> * balancing on
>   behalf of nohz CPUs, especially with increasing number of sockets and
>   cores in the platform.

If the purpose is to keep sockets idle, doing things per node doesn't
seem like a fine plan, since we're having nodes <= socket machines these
days.




  reply	other threads:[~2009-12-14 22:21 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-11  1:27 [patch 0/2] sched: Change nohz ilb logic from pull to push model venkatesh.pallipadi
2009-12-11  1:27 ` [patch 1/2] sched: Change the " venkatesh.pallipadi
2009-12-14 22:18   ` Peter Zijlstra
2009-12-21 12:13   ` Peter Zijlstra
2009-12-21 13:00     ` Peter Zijlstra
2009-12-23  0:15     ` Pallipadi, Venkatesh
2009-12-11  1:27 ` [patch 2/2] sched: Scale the nohz_tracker logic by making it per NUMA node venkatesh.pallipadi
2009-12-14 22:21   ` Peter Zijlstra [this message]
2009-12-14 22:32     ` Pallipadi, Venkatesh
2009-12-14 22:58       ` Peter Zijlstra
2009-12-15  1:00         ` Pallipadi, Venkatesh
2009-12-15 10:21           ` Peter Zijlstra
2009-12-21 13:11   ` Peter Zijlstra

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