Re: Re: Re: Re: Re: Re: Re: [PATCH v1] sched/numa: add per-process numa_balancing

From: Mel Gorman
Date: Wed Nov 17 2021 - 05:10:24 EST


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