From: Andi Kleen <andi@firstfloor.org>
To: Gautham R Shenoy <ego@in.ibm.com>
Cc: "Ingo Molnar" <mingo@elte.hu>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org,
Suresh Siddha <suresh.b.siddha@intel.com>,
"Balbir Singh" <balbir@in.ibm.com>
Subject: Re: [PATCH v2 1/2] sched: Nominate idle load balancer from a semi-idle package.
Date: Fri, 03 Apr 2009 09:04:42 +0200 [thread overview]
Message-ID: <87hc16kyk5.fsf@basil.nowhere.org> (raw)
In-Reply-To: <20090402123829.14569.67639.stgit@sofia.in.ibm.com> (Gautham R. Shenoy's message of "Thu, 02 Apr 2009 18:08:29 +0530")
Gautham R Shenoy <ego@in.ibm.com> writes:
>
> Improve the algorithm to nominate the idle load balancer from a semi idle
> cores/packages thereby increasing the probability of the cores/packages being
> in deeper sleep states for longer duration.
The basic patch looks good.
In theory you could also look for a nearby nohz balancer in the end
to optimize traffic on the interconnect of a larger NUMA system,
but it's probably not worth it.
>
> The algorithm is activated only when sched_mc/smt_power_savings != 0.
But it seems to me that this check could be dropped and doing it
unconditionally, because idle balancing doesn't need much memory
bandwith or cpu power, so always putting it nearby is good.
-Ani
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-04-03 7:04 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-02 12:38 [PATCH v2 0/2] sched: Nominate a power-efficient ILB Gautham R Shenoy
2009-04-02 12:38 ` [PATCH v2 1/2] sched: Nominate idle load balancer from a semi-idle package Gautham R Shenoy
2009-04-02 15:52 ` Jaswinder Singh Rajput
2009-04-03 14:59 ` Gautham R Shenoy
2009-04-03 15:14 ` Randy Dunlap
2009-04-03 7:04 ` Andi Kleen [this message]
2009-04-03 15:11 ` Gautham R Shenoy
2009-04-02 12:38 ` [PATCH v2 2/2] sched: Nominate a power-efficient ilb in select_nohz_balancer() Gautham R Shenoy
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