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authorRik van Riel <riel@redhat.com>2014-06-23 11:41:34 -0400
committerIngo Molnar <mingo@kernel.org>2014-07-05 11:17:39 +0200
commitdb015daedb56251b73f956f70b3b8813f80d8ee1 (patch)
tree9883ace8d1f2edf4ae39a5f3348eea5e7c96f336 /kernel/sched
parent0132c3e1777ceabc24c7d209b7cbe78c28c03c09 (diff)
downloadop-kernel-dev-db015daedb56251b73f956f70b3b8813f80d8ee1.zip
op-kernel-dev-db015daedb56251b73f956f70b3b8813f80d8ee1.tar.gz
sched/numa: Rework best node setting in task_numa_migrate()
Fix up the best node setting in task_numa_migrate() to deal with a task in a pseudo-interleaved NUMA group, which is already running in the best location. Set the task's preferred nid to the current nid, so task migration is not retried at a high rate. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: mgorman@suse.de Cc: chegu_vinod@hp.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1403538095-31256-7-git-send-email-riel@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/fair.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9d1734a..7bb2f46 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1354,10 +1354,6 @@ static int task_numa_migrate(struct task_struct *p)
}
}
- /* No better CPU than the current one was found. */
- if (env.best_cpu == -1)
- return -EAGAIN;
-
/*
* If the task is part of a workload that spans multiple NUMA nodes,
* and is migrating into one of the workload's active nodes, remember
@@ -1366,8 +1362,19 @@ static int task_numa_migrate(struct task_struct *p)
* A task that migrated to a second choice node will be better off
* trying for a better one later. Do not set the preferred node here.
*/
- if (p->numa_group && node_isset(env.dst_nid, p->numa_group->active_nodes))
- sched_setnuma(p, env.dst_nid);
+ if (p->numa_group) {
+ if (env.best_cpu == -1)
+ nid = env.src_nid;
+ else
+ nid = env.dst_nid;
+
+ if (node_isset(nid, p->numa_group->active_nodes))
+ sched_setnuma(p, env.dst_nid);
+ }
+
+ /* No better CPU than the current one was found. */
+ if (env.best_cpu == -1)
+ return -EAGAIN;
/*
* Reset the scan period if the task is being rescheduled on an
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