Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
sched/fair: Only set slice protection at pick time
We should not (re)set slice protection in the sched_change pattern
which calls put_prev_task() / set_next_task().
Fixes: 63304558ba5d ("sched/eevdf: Curb wakeup-preemption")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Shubhang Kaushik <shubhang@os.amperecomputing.com>
Link: https://patch.msgid.link/20260219080624.561421378%40infradead.org
+6
-5
+6
-5
kernel/sched/fair.c
+6
-5
kernel/sched/fair.c
···
5445
5445
}
5446
5446
5447
5447
static void
5448
-
set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
5448
+
set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, bool first)
5449
5449
{
5450
5450
clear_buddies(cfs_rq, se);
5451
5451
···
5460
5460
__dequeue_entity(cfs_rq, se);
5461
5461
update_load_avg(cfs_rq, se, UPDATE_TG);
5462
5462
5463
-
set_protect_slice(cfs_rq, se);
5463
+
if (first)
5464
+
set_protect_slice(cfs_rq, se);
5464
5465
}
5465
5466
5466
5467
update_stats_curr_start(cfs_rq, se);
···
8979
8978
pse = parent_entity(pse);
8980
8979
}
8981
8980
if (se_depth >= pse_depth) {
8982
-
set_next_entity(cfs_rq_of(se), se);
8981
+
set_next_entity(cfs_rq_of(se), se, true);
8983
8982
se = parent_entity(se);
8984
8983
}
8985
8984
}
8986
8985
8987
8986
put_prev_entity(cfs_rq, pse);
8988
-
set_next_entity(cfs_rq, se);
8987
+
set_next_entity(cfs_rq, se, true);
8989
8988
8990
8989
__set_next_task_fair(rq, p, true);
8991
8990
}
···
13599
13598
for_each_sched_entity(se) {
13600
13599
struct cfs_rq *cfs_rq = cfs_rq_of(se);
13601
13600
13602
-
set_next_entity(cfs_rq, se);
13601
+
set_next_entity(cfs_rq, se, first);
13603
13602
/* ensure bandwidth has been allocated on our new cfs_rq */
13604
13603
account_cfs_rq_runtime(cfs_rq, 0);
13605
13604
}