Date:   Wed, 17 Nov 2021 10:10:08 +0000
From:   Mel Gorman <mgorman@suse.de>
To:     Gang Li <ligang.bdlg@bytedance.com>
Cc:     Jonathan Corbet <corbet@lwn.net>, Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        linux-api@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
        linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org
Subject: Re: Re: Re: Re: Re: Re: Re: [PATCH v1] sched/numa: add per-process
 numa_balancing
Message-ID: <20211117101008.GB3301@suse.de>
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On Wed, Nov 17, 2021 at 05:38:28PM +0800, Gang Li wrote:
> On 11/17/21 4:29 PM, Mel Gorman wrote:
> > 
> > It's a bit vague but if you wanted to put together the outline, I'd read
> > over it. Note that this was all in the context of trying to introduce an
> 
> Sorry, maybe I shouldn't propose new feature in this context.
> 
> > API like
> > 
> > Disable/enable per-process numa balancing:
> >          prctl(PR_NUMA_BALANCING, PR_SET_NUMA_BALANCING, 0/1);
> > 
> > i.e. one that controlled both enabling and disabling. You also have
> > the option of introducing the NUMAB equivalent of PR_SET_THP_DISABLE --
> > an API that is explicitly about disabling *only*.
> > 
> 
> If those APIs are ok with you, I will send v2 soon.
> 
> 1. prctl(PR_NUMA_BALANCING, PR_SET_THP_DISABLE);

It would be (PR_SET_NUMAB_DISABLE, 1) 

> 2. prctl(PR_NUMA_BALANCING, PR_SET_THP_ENABLE);

An enable prctl will have the same problems as
prctl(PR_NUMA_BALANCING, PR_SET_NUMA_BALANCING, 0/1) -- it should have
meaning if the numa_balancing sysctl is disabled.

> 3. prctl(PR_NUMA_BALANCING, PR_GET_THP);
> 

PR_GET_NUMAB_DISABLE

-- 
Mel Gorman
SUSE Labs