Messages in this thread Patch in this message | | | Date | Thu, 8 May 2014 03:42:53 -0700 | From | tip-bot for Rik van Riel <> | Subject | [tip:sched/core] sched/numa: Retry placement more frequently when misplaced |
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Commit-ID: 5085e2a328849bdee6650b32d52c87c3788ab01c Gitweb: http://git.kernel.org/tip/5085e2a328849bdee6650b32d52c87c3788ab01c Author: Rik van Riel <riel@redhat.com> AuthorDate: Fri, 11 Apr 2014 13:00:28 -0400 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Wed, 7 May 2014 13:33:46 +0200
sched/numa: Retry placement more frequently when misplaced
When tasks have not converged on their preferred nodes yet, we want to retry fairly often, to make sure we do not migrate a task's memory to an undesirable location, only to have to move it again later.
This patch reduces the interval at which migration is retried, when the task's numa_scan_period is small.
Signed-off-by: Rik van Riel <riel@redhat.com> Tested-by: Vinod Chegu <chegu_vinod@hp.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1397235629-16328-3-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/sched/fair.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f6457b6..ecea8d9 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1326,12 +1326,15 @@ static int task_numa_migrate(struct task_struct *p) /* Attempt to migrate a task to a CPU on the preferred node. */ static void numa_migrate_preferred(struct task_struct *p) { + unsigned long interval = HZ; + /* This task has no NUMA fault statistics yet */ if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults_memory)) return; /* Periodically retry migrating the task to the preferred node */ - p->numa_migrate_retry = jiffies + HZ; + interval = min(interval, msecs_to_jiffies(p->numa_scan_period) / 16); + p->numa_migrate_retry = jiffies + interval; /* Success if task is already running on preferred CPU */ if (task_node(p) == p->numa_preferred_nid)
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