diff options
| author | Paul Turner <pjt@google.com> | 2011-07-21 18:43:38 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-08-14 12:03:44 +0200 |
| commit | 8cb120d3e41a0464a559d639d519cef563717a4e (patch) | |
| tree | 4d17ae0d3d9a18cb502e5d098bd48b7436620754 /kernel/sched.c | |
| parent | sched: Prevent buddy interactions with throttled entities (diff) | |
| download | linux-8cb120d3e41a0464a559d639d519cef563717a4e.tar.xz linux-8cb120d3e41a0464a559d639d519cef563717a4e.zip | |
sched: Migrate throttled tasks on HOTPLUG
Throttled tasks are invisisble to cpu-offline since they are not eligible for
selection by pick_next_task(). The regular 'escape' path for a thread that is
blocked at offline is via ttwu->select_task_rq, however this will not handle a
throttled group since there are no individual thread wakeups on an unthrottle.
Resolve this by unthrottling offline cpus so that threads can be migrated.
Signed-off-by: Paul Turner <pjt@google.com>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110721184757.989000590@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 5db05f6fb470..397317248ddd 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6335,6 +6335,30 @@ static void calc_global_load_remove(struct rq *rq) rq->calc_load_active = 0; } +#ifdef CONFIG_CFS_BANDWIDTH +static void unthrottle_offline_cfs_rqs(struct rq *rq) +{ + struct cfs_rq *cfs_rq; + + for_each_leaf_cfs_rq(rq, cfs_rq) { + struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); + + if (!cfs_rq->runtime_enabled) + continue; + + /* + * clock_task is not advancing so we just need to make sure + * there's some valid quota amount + */ + cfs_rq->runtime_remaining = cfs_b->quota; + if (cfs_rq_throttled(cfs_rq)) + unthrottle_cfs_rq(cfs_rq); + } +} +#else +static void unthrottle_offline_cfs_rqs(struct rq *rq) {} +#endif + /* * Migrate all tasks from the rq, sleeping tasks will be migrated by * try_to_wake_up()->select_task_rq(). @@ -6360,6 +6384,9 @@ static void migrate_tasks(unsigned int dead_cpu) */ rq->stop = NULL; + /* Ensure any throttled groups are reachable by pick_next_task */ + unthrottle_offline_cfs_rqs(rq); + for ( ; ; ) { /* * There's this thread running, bail when that's the only |