[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20181105145400.935-3-patrick.bellasi@arm.com>
Date: Mon, 5 Nov 2018 14:53:59 +0000
From: Patrick Bellasi <patrick.bellasi@....com>
To: linux-kernel@...r.kernel.org
Cc: Ingo Molnar <mingo@...hat.com>,
Peter Zijlstra <peterz@...radead.org>,
Vincent Guittot <vincent.guittot@...aro.org>,
Quentin Perret <quentin.perret@....com>,
Dietmar Eggemann <dietmar.eggemann@....com>,
Morten Rasmussen <morten.rasmussen@....com>,
Juri Lelli <juri.lelli@...hat.com>,
Todd Kjos <tkjos@...gle.com>,
Steve Muckle <smuckle@...gle.com>,
Suren Baghdasaryan <surenb@...gle.com>,
Ingo Molnar <mingo@...nel.org>
Subject: [PATCH v2 2/3] sched/fair: util_est: mask UTIL_AVG_UNCHANGED usages
The _task_util_est() is mainly used to add/remove the task contribution
to/from the rq's estimated utilization at task enqueue/dequeue time.
In both cases we ensure the UTIL_AVG_UNCHANGED flag is set to keep
consistency between enqueue and dequeue time while still being
transparent to update_load_avg calls which will eventually reset the
flag.
Let's move the flag forcing within _task_util_est() itself so that we
can simplify calling code by hiding that estimated utilization
implementation detail into one of its internal functions.
This will affect also the "public" API task_util_est() but we know that
the flag will (eventually) impact just on the LSB of the estimated
utilization, thus it's certainly acceptable.
Signed-off-by: Patrick Bellasi <patrick.bellasi@....com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: linux-kernel@...r.kernel.org
---
kernel/sched/fair.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 473a9cc559e8..aeb37fe4dbb1 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3604,7 +3604,7 @@ static inline unsigned long _task_util_est(struct task_struct *p)
{
struct util_est ue = READ_ONCE(p->se.avg.util_est);
- return max(ue.ewma, ue.enqueued);
+ return (max(ue.ewma, ue.enqueued) | UTIL_AVG_UNCHANGED);
}
static inline unsigned long task_util_est(struct task_struct *p)
@@ -3622,7 +3622,7 @@ static inline void util_est_enqueue(struct cfs_rq *cfs_rq,
/* Update root cfs_rq's estimated utilization */
enqueued = cfs_rq->avg.util_est.enqueued;
- enqueued += (_task_util_est(p) | UTIL_AVG_UNCHANGED);
+ enqueued += _task_util_est(p);
WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued);
}
@@ -3650,8 +3650,7 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
/* Update root cfs_rq's estimated utilization */
ue.enqueued = cfs_rq->avg.util_est.enqueued;
- ue.enqueued -= min_t(unsigned int, ue.enqueued,
- (_task_util_est(p) | UTIL_AVG_UNCHANGED));
+ ue.enqueued -= min_t(unsigned int, ue.enqueued, _task_util_est(p));
WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued);
/*
@@ -6292,7 +6291,7 @@ static unsigned long cpu_util_without(int cpu, struct task_struct *p)
*/
if (unlikely(task_on_rq_queued(p) || current == p)) {
estimated -= min_t(unsigned int, estimated,
- (_task_util_est(p) | UTIL_AVG_UNCHANGED));
+ _task_util_est(p));
}
util = max(util, estimated);
}
--
2.18.0
Powered by blists - more mailing lists