linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mel Gorman <mgorman@suse.de>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ben Segall <bsegall@google.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Phil Auld <pauld@redhat.com>, Parth Shah <parth@linux.ibm.com>,
	Valentin Schneider <valentin.schneider@arm.com>
Subject: Re: [RFC 2/4] sched/numa: replace runnable_load_avg by load_avg
Date: Wed, 12 Feb 2020 16:04:31 +0000	[thread overview]
Message-ID: <20200212160431.GW3420@suse.de> (raw)
In-Reply-To: <CAKfTPtAJE_eDgR8dmScgVbOgS9sQSJg27Mw62Z1htMCmgN_Yew@mail.gmail.com>

On Wed, Feb 12, 2020 at 04:03:28PM +0100, Vincent Guittot wrote:
> > Ok, so this is essentially group_is_overloaded.
> >
> >
> > > +     if ((ns->nr_running < ns->weight) ||
> > > +         ((ns->compute_capacity * 100) > (ns->util * imbalance_pct)))
> > > +             return node_has_spare;
> > > +
> >
> > And this is group_has_capacity. What I did was have a common helper
> > for both NUMA and normal load balancing and translated the fields from
> > sg_lb_stats and numa_stats into a common helper. This is to prevent them
> > getting out of sync. The conversion was incomplete in my case but in
> > principle, both NUMA and CPU load balancing should use common helpers or
> > they'll get out of sync.
> 
> I fact, I wanted to keep this patch simple and readable for the 1st
> version in order to not afraid people from reviewing it. That's the
> main reason I didn't merge it with load_balance but i agree that some
> common helper function might be possible.
> 

Makes sense.

> Also the struct sg_lb_stats has a lot more fields compared to struct numa_stats
> 

Yes, I considered reusing the same structure and decided against it. I
simply created a common helper. It's trivial enough to do on top after
the fact in the name of clarity. Fundamentally it's cosmetic.

> Then, I wonder if we could end up with different rules for numa like
> taking into account some NUMA specifics metrics to classify the node
> 

Well, we could but right now they should be the same. As it is, the NUMA
balancer and load balancer overrule each other. I think the scope for
changing that without causing regressions is limited.

-- 
Mel Gorman
SUSE Labs

  reply	other threads:[~2020-02-12 16:04 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-11 17:46 [PATCH 0/4] remove runnable_load_avg and improve group_classify Vincent Guittot
2020-02-11 17:46 ` [PATCH 1/4] sched/fair: reorder enqueue/dequeue_task_fair path Vincent Guittot
2020-02-12 13:20   ` Mel Gorman
2020-02-12 14:47     ` Vincent Guittot
2020-02-12 16:11       ` Mel Gorman
2020-02-11 17:46 ` [RFC 2/4] sched/numa: replace runnable_load_avg by load_avg Vincent Guittot
2020-02-12 13:37   ` Mel Gorman
2020-02-12 15:03     ` Vincent Guittot
2020-02-12 16:04       ` Mel Gorman [this message]
2020-02-12 19:49     ` Mel Gorman
2020-02-12 21:29       ` Mel Gorman
2020-02-13  8:05       ` Vincent Guittot
2020-02-13  9:24         ` Mel Gorman
     [not found]         ` <20200213131658.9600-1-hdanton@sina.com>
2020-02-13 13:46           ` Mel Gorman
2020-02-13 15:00             ` Phil Auld
2020-02-13 15:14               ` Mel Gorman
2020-02-13 16:11                 ` Vincent Guittot
2020-02-13 16:34                   ` Mel Gorman
2020-02-13 16:38                     ` Vincent Guittot
2020-02-13 17:02                       ` Mel Gorman
2020-02-13 17:15                         ` Vincent Guittot
2020-02-11 17:46 ` [RFC 3/4] sched/fair: replace runnable load average by runnable average Vincent Guittot
2020-02-12 14:30   ` Mel Gorman
2020-02-14  7:42     ` Vincent Guittot
2020-02-13 17:36   ` Peter Zijlstra
2020-02-14  7:43     ` Vincent Guittot
2020-02-11 17:46 ` [RFC 4/4] sched/fair: Take into runnable_avg to classify group Vincent Guittot
2020-02-13 18:32   ` Valentin Schneider
2020-02-13 18:37     ` Valentin Schneider
2020-02-14  7:48       ` Vincent Guittot
2020-02-11 21:04 ` [PATCH 0/4] remove runnable_load_avg and improve group_classify Mel Gorman
2020-02-12  8:16   ` Vincent Guittot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200212160431.GW3420@suse.de \
    --to=mgorman@suse.de \
    --cc=bsegall@google.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=parth@linux.ibm.com \
    --cc=pauld@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=valentin.schneider@arm.com \
    --cc=vincent.guittot@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).