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| author | Ben Segall <bsegall@google.com> | 2014-05-15 15:59:20 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-05-22 11:16:25 +0200 |
| commit | 3944a9274ef6cda0cc282daf0739832f661670f7 (patch) | |
| tree | 915704002a970ef8e8f359734355a0784d935088 /kernel | |
| parent | 6669dc89078da020241e78e5589489e494203332 (diff) | |
| download | linux-stable-3944a9274ef6cda0cc282daf0739832f661670f7.tar.gz linux-stable-3944a9274ef6cda0cc282daf0739832f661670f7.tar.bz2 linux-stable-3944a9274ef6cda0cc282daf0739832f661670f7.zip | |
sched: Fix exec_start/task_hot on migrated tasks
task_hot checks exec_start on any runnable task, but if it has been
migrated since the it last ran, then exec_start is a clock_task from
another cpu. If the old cpu's clock_task was sufficiently far ahead of
this cpu's then the task will not be considered for another migration
until it has run. Instead reset exec_start whenever a task is migrated,
since it is presumably no longer hot anyway.
Signed-off-by: Ben Segall <bsegall@google.com>
[ Made it compile. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140515225920.7179.13924.stgit@sword-of-the-dawn.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 28ccf502c63c..dd3fa14a2998 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4544,6 +4544,9 @@ migrate_task_rq_fair(struct task_struct *p, int next_cpu) atomic_long_add(se->avg.load_avg_contrib, &cfs_rq->removed_load); } + + /* We have migrated, no longer consider this task hot */ + se->exec_start = 0; } #endif /* CONFIG_SMP */ |