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From: Peter Zijlstra <peterz@infradead.org>
To: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>, Ingo Molnar <mingo@redhat.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Stefano Garzarella <sgarzare@redhat.com>
Subject: Re: [PATCH] sched/fair: don't NUMA balance for kthreads
Date: Tue, 26 May 2020 22:00:15 +0200
Message-ID: <20200526200015.GG325280@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <jhjpnaqtztl.mognet@arm.com>

On Tue, May 26, 2020 at 05:40:06PM +0100, Valentin Schneider wrote:

> > Change the task_tick_numa() check to exclude kernel threads in general,
> > as it doesn't make sense to attempt ot balance for kthreads anyway.
> >
> 
> Does it? (this isn't a rethorical question)
> 
> Suppose a given kthread ends up doing more accesses to some pages
> (via use_mm()) than the other threads that access them, wouldn't it make
> sense to take that into account when it comes to NUMA balancing?

Well, task_tick_numa() tries and farm off a bunch of actual work to
task_work_add(), and there's so very little userspace for a kernel
thread to return to... :-)



  reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-26 15:38 Jens Axboe
2020-05-26 16:37 ` [tip: sched/urgent] sched/fair: Don't " tip-bot2 for Jens Axboe
2020-05-26 16:40 ` [PATCH] sched/fair: don't " Valentin Schneider
2020-05-26 20:00   ` Peter Zijlstra [this message]
2020-05-26 23:42     ` Valentin Schneider

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