Messages in this thread Patch in this message | | | From | riel@redhat ... | Subject | [PATCH 6/7] sched,numa: rework best node setting in task_numa_migrate | Date | Mon, 23 Jun 2014 11:41:34 -0400 |
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From: Rik van Riel <riel@redhat.com>
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> --- kernel/sched/fair.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d525451..ee35576 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 -- 1.8.5.3
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