From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>,
Rik van Riel <riel@surriel.com>, Yi Wang <wang.yi59@zte.com.cn>,
zhong.weidong@zte.com.cn, Yi Liu <liu.yi24@zte.com.cn>,
Frederic Weisbecker <frederic@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH v2] sched/core: Don't mix isolcpus and housekeeping CPUs
Date: Wed, 24 Oct 2018 16:00:02 +0530 [thread overview]
Message-ID: <20181024103002.GB18466@linux.vnet.ibm.com> (raw)
In-Reply-To: <20181024100323.GO3109@worktop.c.hoisthospitality.com>
* Peter Zijlstra <peterz@infradead.org> [2018-10-24 12:03:23]:
> It appears to me the for_each_online_node() iteration in
> task_numa_migrate() needs an addition test to see if the selected node
> has any CPUs in the relevant sched_domain _at_all_.
>
Yes, this should work.
Yi Wang does this extra check a little differently.
http://lkml.kernel.org/r/1540177516-38613-1-git-send-email-wang.yi59@zte.com.cn
However the last time I had posted you didn't like that approach.
http://lkml.kernel.org/r/20170406073659.y6ubqriyshax4v4m@hirez.programming.kicks-ass.net
Further, I would think the number of times, we would be calling
sched_setaffinity would be far less than task_numa_migrate().
In the regular case, where we never have isolcpus, we add this extra check.
Also what does it mean for a task to have its cpu affinity set to a mix of
isolcpus and non isolcpus.
Also should we be updating update_numa_stats accordingly? While the problem
may not be apparent there but we are counting the load and compute capacity
of isolcpus.
--
Thanks and Regards
Srikar Dronamraju
next prev parent reply other threads:[~2018-10-24 10:30 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-24 3:02 [PATCH v2] sched/core: Don't mix isolcpus and housekeeping CPUs Srikar Dronamraju
2018-10-24 8:56 ` Mel Gorman
2018-10-24 9:46 ` Srikar Dronamraju
2018-10-24 10:15 ` Peter Zijlstra
2018-10-24 10:41 ` Srikar Dronamraju
2018-10-24 11:21 ` Mel Gorman
2018-10-24 10:31 ` Mel Gorman
2018-10-24 10:03 ` Peter Zijlstra
2018-10-24 10:30 ` Srikar Dronamraju [this message]
2018-10-25 0:07 ` Peter Zijlstra
2018-10-25 17:30 ` Srikar Dronamraju
2018-10-26 8:41 ` Peter Zijlstra
2018-10-26 9:30 ` Srikar Dronamraju
2018-10-25 18:23 ` Srikar Dronamraju
2018-10-26 8:42 ` Peter Zijlstra
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