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From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: subhra mazumdar <subhra.mazumdar@oracle.com>
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	mingo@redhat.com, tglx@linutronix.de,
	prakash.sangappa@oracle.com, dhaval.giani@oracle.com,
	daniel.lezcano@linaro.org, vincent.guittot@linaro.org,
	viresh.kumar@linaro.org, tim.c.chen@linux.intel.com,
	mgorman@techsingularity.net
Subject: Re: [RFC PATCH 3/3] sched: introduce tunables to control soft affinity
Date: Thu, 18 Jul 2019 15:38:16 +0530	[thread overview]
Message-ID: <20190718100816.GA19218@linux.vnet.ibm.com> (raw)
In-Reply-To: <20190626224718.21973-4-subhra.mazumdar@oracle.com>

* subhra mazumdar <subhra.mazumdar@oracle.com> [2019-06-26 15:47:18]:

> For different workloads the optimal "softness" of soft affinity can be
> different. Introduce tunables sched_allowed and sched_preferred that can
> be tuned via /proc. This allows to chose at what utilization difference
> the scheduler will chose cpus_allowed over cpus_preferred in the first
> level of search. Depending on the extent of data sharing, cache coherency
> overhead of the system etc. the optimal point may vary.
> 
> Signed-off-by: subhra mazumdar <subhra.mazumdar@oracle.com>
> ---

Correct me but this patchset only seems to be concentrated on the wakeup
path, I don't see any changes in the regular load balancer or the
numa-balancer. If system is loaded or tasks are CPU intensive, then wouldn't
these tasks be moved to cpus_allowed instead of cpus_preferred and hence
breaking this soft affinity.

-- 
Thanks and Regards
Srikar Dronamraju


  reply	other threads:[~2019-07-18 10:08 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-26 22:47 [RFC PATCH 0/3] Scheduler Soft Affinity subhra mazumdar
2019-06-26 22:47 ` [RFC PATCH 1/3] sched: Introduce new interface for scheduler soft affinity subhra mazumdar
2019-07-02 16:23   ` Peter Zijlstra
2019-07-02 16:29   ` Peter Zijlstra
2019-06-26 22:47 ` [RFC PATCH 2/3] sched: change scheduler to give preference to soft affinity CPUs subhra mazumdar
2019-07-02 17:28   ` Peter Zijlstra
2019-07-17  3:01     ` Subhra Mazumdar
2019-07-18 11:37       ` Peter Zijlstra
2019-07-19  2:55         ` Subhra Mazumdar
2019-06-26 22:47 ` [RFC PATCH 3/3] sched: introduce tunables to control soft affinity subhra mazumdar
2019-07-18 10:08   ` Srikar Dronamraju [this message]
2019-07-19  7:23     ` Subhra Mazumdar

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