From: Peter Zijlstra <peterz@infradead.org>
To: Mel Gorman <mgorman@suse.de>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Ingo Molnar <mingo@kernel.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 08/16] sched: Reschedule task on preferred NUMA node once selected
Date: Thu, 11 Jul 2013 14:30:38 +0200 [thread overview]
Message-ID: <20130711123038.GH25631@dyad.programming.kicks-ass.net> (raw)
In-Reply-To: <1373536020-2799-9-git-send-email-mgorman@suse.de>
On Thu, Jul 11, 2013 at 10:46:52AM +0100, Mel Gorman wrote:
> @@ -829,10 +854,29 @@ static void task_numa_placement(struct task_struct *p)
> }
> }
>
> - /* Update the tasks preferred node if necessary */
> + /*
> + * Record the preferred node as the node with the most faults,
> + * requeue the task to be running on the idlest CPU on the
> + * preferred node and reset the scanning rate to recheck
> + * the working set placement.
> + */
> if (max_faults && max_nid != p->numa_preferred_nid) {
> + int preferred_cpu;
> +
> + /*
> + * If the task is not on the preferred node then find the most
> + * idle CPU to migrate to.
> + */
> + preferred_cpu = task_cpu(p);
> + if (cpu_to_node(preferred_cpu) != max_nid) {
> + preferred_cpu = find_idlest_cpu_node(preferred_cpu,
> + max_nid);
> + }
> +
> + /* Update the preferred nid and migrate task if possible */
> p->numa_preferred_nid = max_nid;
> p->numa_migrate_seq = 0;
> + migrate_task_to(p, preferred_cpu);
> }
> }
Now what happens if the migrations fails? We set numa_preferred_nid to max_nid
but then never re-try the migration. Should we not re-try the migration every
so often, regardless of whether max_nid changed?
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next prev parent reply other threads:[~2013-07-11 12:31 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-11 9:46 [PATCH 0/16] Basic scheduler support for automatic NUMA balancing V4 Mel Gorman
2013-07-11 9:46 ` [PATCH 01/16] mm: numa: Document automatic NUMA balancing sysctls Mel Gorman
2013-07-11 9:46 ` [PATCH 02/16] sched: Track NUMA hinting faults on per-node basis Mel Gorman
2013-07-11 9:46 ` [PATCH 03/16] mm: numa: Account for THP numa hinting faults on the correct node Mel Gorman
2013-07-11 9:46 ` [PATCH 04/16] mm: numa: Do not migrate or account for hinting faults on the zero page Mel Gorman
2013-07-11 11:21 ` Peter Zijlstra
2013-07-11 12:42 ` Mel Gorman
2013-07-11 9:46 ` [PATCH 05/16] sched: Select a preferred node with the most numa hinting faults Mel Gorman
2013-07-11 11:23 ` Peter Zijlstra
2013-07-11 12:53 ` Mel Gorman
2013-07-11 9:46 ` [PATCH 06/16] sched: Update NUMA hinting faults once per scan Mel Gorman
2013-07-11 9:46 ` [PATCH 07/16] sched: Favour moving tasks towards the preferred node Mel Gorman
2013-07-11 9:46 ` [PATCH 08/16] sched: Reschedule task on preferred NUMA node once selected Mel Gorman
2013-07-11 12:30 ` Peter Zijlstra [this message]
2013-07-11 13:03 ` Mel Gorman
2013-07-11 13:11 ` Peter Zijlstra
2013-07-11 14:09 ` Mel Gorman
2013-07-12 10:14 ` Peter Zijlstra
2013-07-12 10:28 ` Mel Gorman
2013-07-11 9:46 ` [PATCH 09/16] sched: Add infrastructure for split shared/private accounting of NUMA hinting faults Mel Gorman
2013-07-11 9:46 ` [PATCH 10/16] sched: Increase NUMA PTE scanning when a new preferred node is selected Mel Gorman
2013-07-11 9:46 ` [PATCH 11/16] sched: Check current->mm before allocating NUMA faults Mel Gorman
2013-07-11 9:46 ` [PATCH 12/16] sched: Set the scan rate proportional to the size of the task being scanned Mel Gorman
2013-07-11 9:46 ` [PATCH 13/16] mm: numa: Scan pages with elevated page_mapcount Mel Gorman
2013-07-11 9:46 ` [PATCH 14/16] sched: Remove check that skips small VMAs Mel Gorman
2013-07-11 9:46 ` [PATCH 15/16] sched: Set preferred NUMA node based on number of private faults Mel Gorman
2013-07-11 9:47 ` [PATCH 16/16] sched: Select least loaded CPU on preferred NUMA node Mel Gorman
2013-07-11 12:39 ` Peter Zijlstra
2013-07-11 13:24 ` Mel Gorman
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