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sched/pelt: Use rq_clock_task() for hw_pressure

commit 97450eb90965 ("sched/pelt: Remove shift of thermal clock")
removed the decay_shift for hw_pressure. This commit uses the
sched_clock_task() in sched_tick() while it replaces the
sched_clock_task() with rq_clock_pelt() in __update_blocked_others().
This could bring inconsistence. One possible scenario I can think of
is in ___update_load_sum():

u64 delta = now - sa->last_update_time

'now' could be calculated by rq_clock_pelt() from
__update_blocked_others(), and last_update_time was calculated by
rq_clock_task() previously from sched_tick(). Usually the former
chases after the latter, it cause a very large 'delta' and brings
unexpected behavior.

Fixes: 97450eb90965 ("sched/pelt: Remove shift of thermal clock")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Hongyan Xia <hongyan.xia2@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20240827112607.181206-1-yu.c.chen@intel.com

authored by

Chen Yu and committed by
Peter Zijlstra 84d26528 5d871a63

+2 -1
+2 -1
kernel/sched/fair.c
··· 9719 9719 9720 9720 hw_pressure = arch_scale_hw_pressure(cpu_of(rq)); 9721 9721 9722 + /* hw_pressure doesn't care about invariance */ 9722 9723 decayed = update_rt_rq_load_avg(now, rq, curr_class == &rt_sched_class) | 9723 9724 update_dl_rq_load_avg(now, rq, curr_class == &dl_sched_class) | 9724 - update_hw_load_avg(now, rq, hw_pressure) | 9725 + update_hw_load_avg(rq_clock_task(rq), rq, hw_pressure) | 9725 9726 update_irq_load_avg(rq, 0); 9726 9727 9727 9728 if (others_have_blocked(rq))