From: Mel Gorman <mgorman@techsingularity.net>
To: Hillf Danton <hdanton@sina.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Juri Lelli <juri.lelli@redhat.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>,
Valentin Schneider <valentin.schneider@arm.com>,
Phil Auld <pauld@redhat.com>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 06/13] sched/numa: Use similar logic to the load balancer for moving between domains with spare capacity
Date: Tue, 18 Feb 2020 10:53:55 +0000 [thread overview]
Message-ID: <20200218105355.GN3466@techsingularity.net> (raw)
In-Reply-To: <20200218095915.844-1-hdanton@sina.com>
On Tue, Feb 18, 2020 at 05:59:15PM +0800, Hillf Danton wrote:
> > Given that adjust_numa_imbalance takes the imbalance as the first
> > parameter, not a boolean and it's not unconditionally true, I don't
> > get what you mean.
>
> My bad.
>
> > Can you propose a patch on top of the entire series
> > explaining what you suggest please?
>
> I just want to avoid splitting the pair of tasks on the src node as
> described by the comment in adjust_numa_imbalance() across two nodes
> despite idle cpus that are available on the dst node.
>
Ah ok, so yes, this is something that needs to be done but it should be
a separate patch after this series is complete. It's very easy to get it
wrong and introduce regressions so I want to get the NUMA balancer and
load balancer reconciled first.
> If there are more than 2 tasks running on src node then try to migrate
> task to dst node in order to decrease imbalance.
>
That should be happening already because
imbalance = max(0, dst_running - src_running);
I didn't take the absolute difference and excess tasks on the src should
still be able to migrate
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2020-02-18 10:54 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-17 10:43 [PATCH 00/13] Reconcile NUMA balancing decisions with the load balancer v3 Mel Gorman
2020-02-17 10:43 ` [PATCH 01/13] sched/fair: Allow a per-CPU kthread waking a task to stack on the same CPU, to fix XFS performance regression Mel Gorman
2020-02-17 10:43 ` [PATCH 02/13] sched/numa: Trace when no candidate CPU was found on the preferred node Mel Gorman
2020-02-17 10:43 ` [PATCH 03/13] sched/numa: Distinguish between the different task_numa_migrate failure cases Mel Gorman
2020-02-17 10:43 ` [PATCH 04/13] sched/fair: Reorder enqueue/dequeue_task_fair path Mel Gorman
2020-02-17 10:43 ` [PATCH 05/13] sched/numa: Replace runnable_load_avg by load_avg Mel Gorman
2020-02-17 10:43 ` [PATCH 06/13] sched/numa: Use similar logic to the load balancer for moving between domains with spare capacity Mel Gorman
2020-02-17 10:43 ` [PATCH 07/13] sched/pelt: Remove unused runnable load average Mel Gorman
2020-02-17 10:43 ` [PATCH 08/13] sched/pelt: Add a new runnable average signal Mel Gorman
2020-02-17 10:43 ` [PATCH 09/13] sched/fair: Take into account runnable_avg to classify group Mel Gorman
2020-02-17 10:43 ` [PATCH 10/13] sched/numa: Prefer using an idle cpu as a migration target instead of comparing tasks Mel Gorman
2020-02-17 10:44 ` [PATCH 11/13] sched/numa: Find an alternative idle CPU if the CPU is part of an active NUMA balance Mel Gorman
2020-02-17 10:44 ` [PATCH 12/13] sched/numa: Bias swapping tasks based on their preferred node Mel Gorman
2020-02-17 10:44 ` [PATCH 13/13] sched/numa: Stop an exhastive search if a reasonable swap candidate or idle CPU is found Mel Gorman
2020-02-17 13:49 ` [PATCH 00/13] Reconcile NUMA balancing decisions with the load balancer v3 Vincent Guittot
2020-02-17 14:52 ` Peter Zijlstra
2020-02-17 15:31 ` Mel Gorman
2020-02-17 15:14 ` Mel Gorman
2020-02-17 16:15 ` Vincent Guittot
[not found] ` <20200217132019.6684-1-hdanton@sina.com>
2020-02-17 15:06 ` [PATCH 06/13] sched/numa: Use similar logic to the load balancer for moving between domains with spare capacity Mel Gorman
[not found] ` <20200218033244.6860-1-hdanton@sina.com>
2020-02-18 8:47 ` Mel Gorman
[not found] ` <20200218095915.844-1-hdanton@sina.com>
2020-02-18 10:53 ` Mel Gorman [this message]
2020-02-19 13:54 [PATCH 00/13] Reconcile NUMA balancing decisions with the load balancer v4 Mel Gorman
2020-02-19 13:54 ` [PATCH 06/13] sched/numa: Use similar logic to the load balancer for moving between domains with spare capacity Mel Gorman
2020-02-19 14:07 [PATCH 00/13] Reconcile NUMA balancing decisions with the load balancer v5 Mel Gorman
2020-02-19 14:07 ` [PATCH 06/13] sched/numa: Use similar logic to the load balancer for moving between domains with spare capacity Mel Gorman
2020-02-24 9:52 [PATCH 00/13] Reconcile NUMA balancing decisions with the load balancer v6 Mel Gorman
2020-02-24 9:52 ` [PATCH 06/13] sched/numa: Use similar logic to the load balancer for moving between domains with spare capacity Mel Gorman
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