From: Steve Sistare <steven.sistare@oracle.com>
To: mingo@redhat.com, peterz@infradead.org
Cc: subhra.mazumdar@oracle.com, dhaval.giani@oracle.com,
daniel.m.jordan@oracle.com, pavel.tatashin@microsoft.com,
matt@codeblueprint.co.uk, umgwanakikbuti@gmail.com,
riel@redhat.com, jbacik@fb.com, juri.lelli@redhat.com,
valentin.schneider@arm.com, vincent.guittot@linaro.org,
quentin.perret@arm.com, steven.sistare@oracle.com,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 05/10] sched/fair: Hoist idle_stamp up from idle_balance
Date: Mon, 5 Nov 2018 12:08:04 -0800 [thread overview]
Message-ID: <1541448489-19692-6-git-send-email-steven.sistare@oracle.com> (raw)
In-Reply-To: <1541448489-19692-1-git-send-email-steven.sistare@oracle.com>
Move the update of idle_stamp from idle_balance to the call site in
pick_next_task_fair, to prepare for a future patch that adds work to
pick_next_task_fair which must be included in the idle_stamp interval.
No functional change.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
kernel/sched/fair.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c623338..305edf8 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3724,6 +3724,8 @@ static inline bool within_margin(int value, int margin)
WRITE_ONCE(p->se.avg.util_est, ue);
}
+#define IF_SMP(statement) statement
+
static void overload_clear(struct rq *rq)
{
struct sparsemask *overload_cpus;
@@ -3769,6 +3771,8 @@ static inline int idle_balance(struct rq *rq, struct rq_flags *rf)
return 0;
}
+#define IF_SMP(statement) /* empty */
+
static inline void overload_clear(struct rq *rq) {}
static inline void overload_set(struct rq *rq) {}
@@ -6740,8 +6744,17 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
return p;
idle:
+ /*
+ * We must set idle_stamp _before_ calling idle_balance(), such that we
+ * measure the duration of idle_balance() as idle time.
+ */
+ IF_SMP(rq->idle_stamp = rq_clock(rq);)
+
new_tasks = idle_balance(rq, rf);
+ if (new_tasks)
+ IF_SMP(rq->idle_stamp = 0;)
+
/*
* Because idle_balance() releases (and re-acquires) rq->lock, it is
* possible for any higher priority task to appear. In that case we
@@ -9504,12 +9517,6 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf)
u64 curr_cost = 0;
/*
- * We must set idle_stamp _before_ calling idle_balance(), such that we
- * measure the duration of idle_balance() as idle time.
- */
- this_rq->idle_stamp = rq_clock(this_rq);
-
- /*
* Do not pull tasks towards !active CPUs...
*/
if (!cpu_active(this_cpu))
@@ -9600,9 +9607,6 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf)
if (this_rq->nr_running != this_rq->cfs.h_nr_running)
pulled_task = -1;
- if (pulled_task)
- this_rq->idle_stamp = 0;
-
rq_repin_lock(this_rq, rf);
return pulled_task;
--
1.8.3.1
next prev parent reply other threads:[~2018-11-05 20:17 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-05 20:07 [PATCH v2 00/10] steal tasks to improve CPU utilization Steve Sistare
2018-11-05 20:08 ` [PATCH v2 01/10] sched: Provide sparsemask, a reduced contention bitmap Steve Sistare
2018-11-05 20:08 ` [PATCH v2 02/10] sched/topology: Provide hooks to allocate data shared per LLC Steve Sistare
2018-11-05 20:08 ` [PATCH v2 03/10] sched/topology: Provide cfs_overload_cpus bitmap Steve Sistare
2018-11-05 20:08 ` [PATCH v2 04/10] sched/fair: Dynamically update cfs_overload_cpus Steve Sistare
2018-11-05 20:08 ` Steve Sistare [this message]
2018-11-05 20:08 ` [PATCH v2 06/10] sched/fair: Generalize the detach_task interface Steve Sistare
2018-11-05 20:08 ` [PATCH v2 07/10] sched/fair: Provide can_migrate_task_llc Steve Sistare
2018-11-05 20:08 ` [PATCH v2 08/10] sched/fair: Steal work from an overloaded CPU when CPU goes idle Steve Sistare
2018-11-05 20:08 ` [PATCH v2 09/10] sched/fair: disable stealing if too many NUMA nodes Steve Sistare
2018-11-05 20:08 ` [PATCH v2 10/10] sched/fair: Provide idle search schedstats Steve Sistare
2018-11-06 17:52 ` [PATCH v2 00/10] steal tasks to improve CPU utilization Valentin Schneider
2018-11-06 18:14 ` Steven Sistare
2018-11-09 12:58 ` Steven Sistare
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