diff options
author | Vincent Guittot <vincent.guittot@linaro.org> | 2020-05-13 15:55:28 +0200 |
---|---|---|
committer | Vincent Guittot <vincent.guittot@linaro.org> | 2020-05-25 18:35:51 +0200 |
commit | fd17227f434aefa39beefda581564a37aa007a5c (patch) | |
tree | 05965e203c6846169b9f07c3831f548aa22570ed | |
parent | b4ec8b31a699678f993caf31332f651f26238bc6 (diff) |
sched/fair: Fix unthrottle_cfs_rq() for leaf_cfs_rq listtest/backport-v5.6
commit 39f23ce07b9355d05a64ae303ce20d1c4b92b957 upstream.
Although not exactly identical, unthrottle_cfs_rq() and enqueue_task_fair()
are quite close and follow the same sequence for enqueuing an entity in the
cfs hierarchy. Modify unthrottle_cfs_rq() to use the same pattern as
enqueue_task_fair(). This fixes a problem already faced with the latter and
add an optimization in the last for_each_sched_entity loop.
Fixes: fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
Reported-by Tao Zhou <zohooouoto@zoho.com.cn>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Link: https://lkml.kernel.org/r/20200513135528.4742-1-vincent.guittot@linaro.org
-rw-r--r-- | kernel/sched/fair.c | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 7cd86641b44b..b579546670e3 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4590,7 +4590,6 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) struct rq *rq = rq_of(cfs_rq); struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); struct sched_entity *se; - int enqueue = 1; long task_delta, idle_task_delta; se = cfs_rq->tg->se[cpu_of(rq)]; @@ -4614,21 +4613,41 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) idle_task_delta = cfs_rq->idle_h_nr_running; for_each_sched_entity(se) { if (se->on_rq) - enqueue = 0; + break; + cfs_rq = cfs_rq_of(se); + enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP); + + cfs_rq->h_nr_running += task_delta; + cfs_rq->idle_h_nr_running += idle_task_delta; + /* end evaluation on encountering a throttled cfs_rq */ + if (cfs_rq_throttled(cfs_rq)) + goto unthrottle_throttle; + } + + for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); - if (enqueue) - enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP); + cfs_rq->h_nr_running += task_delta; cfs_rq->idle_h_nr_running += idle_task_delta; + + /* end evaluation on encountering a throttled cfs_rq */ if (cfs_rq_throttled(cfs_rq)) - break; + goto unthrottle_throttle; + + /* + * One parent has been throttled and cfs_rq removed from the + * list. Add it back to not break the leaf list. + */ + if (throttled_hierarchy(cfs_rq)) + list_add_leaf_cfs_rq(cfs_rq); } - if (!se) - add_nr_running(rq, task_delta); + /* At this point se is NULL and we are at root level*/ + add_nr_running(rq, task_delta); +unthrottle_throttle: /* * The cfs_rq_throttled() breaks in the above iteration can result in * incomplete leaf list maintenance, resulting in triggering the @@ -4637,7 +4656,8 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); - list_add_leaf_cfs_rq(cfs_rq); + if (list_add_leaf_cfs_rq(cfs_rq)) + break; } assert_list_leaf_cfs_rq(rq); |