From: Qais Yousef qais.yousef@arm.com
[ Upstream commit c56ab1b3506ba0e7a872509964b100912bde165d ]
So that it is now uclamp aware.
This fixes a major problem of busy tasks capped with UCLAMP_MAX keeping the system in overutilized state which disables EAS and leads to wasting energy in the long run.
Without this patch running a busy background activity like JIT compilation on Pixel 6 causes the system to be in overutilized state 74.5% of the time.
With this patch this goes down to 9.79%.
It also fixes another problem when long running tasks that have their UCLAMP_MIN changed while running such that they need to upmigrate to honour the new UCLAMP_MIN value. The upmigration doesn't get triggered because overutilized state never gets set in this state, hence misfit migration never happens at tick in this case until the task wakes up again.
Fixes: af24bde8df202 ("sched/uclamp: Add uclamp support to energy_compute()") Signed-off-by: Qais Yousef qais.yousef@arm.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lore.kernel.org/r/20220804143609.515789-7-qais.yousef@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/sched/fair.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index cb4d47441a41..2e782d79e80f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5807,7 +5807,10 @@ static inline void hrtick_update(struct rq *rq) #ifdef CONFIG_SMP static inline bool cpu_overutilized(int cpu) { - return !fits_capacity(cpu_util_cfs(cpu), capacity_of(cpu)); + unsigned long rq_util_min = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MIN); + unsigned long rq_util_max = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MAX); + + return !util_fits_cpu(cpu_util_cfs(cpu), rq_util_min, rq_util_max, cpu); }
static inline void update_overutilized_status(struct rq *rq)