Commit-ID: 0ccb977f4c80b921a8bf6a2c4b8ea0c1fed6553c
Gitweb: http://git.kernel.org/tip/0ccb977f4c80b921a8bf6a2c4b8ea0c1fed6553c
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Tue, 28 Mar 2017 11:08:20 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 30 Mar 2017 09:43:40 +0200
sched/fair: Explicitly generate __update_load_avg() instances
The __update_load_avg() function is an __always_inline because its
used with constant propagation to generate different variants of the
code without having to duplicate it (which would be prone to bugs).
Explicitly instantiate the 3 variants.
Note that most of this is called from rather hot paths, so reducing
branches is good.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/sched/fair.c | 56 ++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 38 insertions(+), 18 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 31453d5..2ac00cf 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2849,7 +2849,7 @@ static u32 __compute_runnable_contrib(u64 n)
* = u_0 + u_1*y + u_2*y^2 + ... [re-labeling u_i --> u_{i+1}]
*/
static __always_inline int
-__update_load_avg(u64 now, int cpu, struct sched_avg *sa,
+___update_load_avg(u64 now, int cpu, struct sched_avg *sa,
unsigned long weight, int running, struct cfs_rq *cfs_rq)
{
u64 delta, scaled_delta, periods;
@@ -2953,6 +2953,28 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa,
return decayed;
}
+static int
+__update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se)
+{
+ return ___update_load_avg(now, cpu, &se->avg, 0, 0, NULL);
+}
+
+static int
+__update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ return ___update_load_avg(now, cpu, &se->avg,
+ se->on_rq * scale_load_down(se->load.weight),
+ cfs_rq->curr == se, NULL);
+}
+
+static int
+__update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq)
+{
+ return ___update_load_avg(now, cpu, &cfs_rq->avg,
+ scale_load_down(cfs_rq->load.weight),
+ cfs_rq->curr != NULL, cfs_rq);
+}
+
/*
* Signed add and clamp on underflow.
*
@@ -3014,6 +3036,9 @@ static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
void set_task_rq_fair(struct sched_entity *se,
struct cfs_rq *prev, struct cfs_rq *next)
{
+ u64 p_last_update_time;
+ u64 n_last_update_time;
+
if (!sched_feat(ATTACH_AGE_LOAD))
return;
@@ -3024,11 +3049,11 @@ void set_task_rq_fair(struct sched_entity *se,
* time. This will result in the wakee task is less decayed, but giving
* the wakee more load sounds not bad.
*/
- if (se->avg.last_update_time && prev) {
- u64 p_last_update_time;
- u64 n_last_update_time;
+ if (!(se->avg.last_update_time && prev))
+ return;
#ifndef CONFIG_64BIT
+ {
u64 p_last_update_time_copy;
u64 n_last_update_time_copy;
@@ -3043,14 +3068,13 @@ void set_task_rq_fair(struct sched_entity *se,
} while (p_last_update_time != p_last_update_time_copy ||
n_last_update_time != n_last_update_time_copy);
+ }
#else
- p_last_update_time = prev->avg.last_update_time;
- n_last_update_time = next->avg.last_update_time;
+ p_last_update_time = prev->avg.last_update_time;
+ n_last_update_time = next->avg.last_update_time;
#endif
- __update_load_avg(p_last_update_time, cpu_of(rq_of(prev)),
- &se->avg, 0, 0, NULL);
- se->avg.last_update_time = n_last_update_time;
- }
+ __update_load_avg_blocked_se(p_last_update_time, cpu_of(rq_of(prev)), se);
+ se->avg.last_update_time = n_last_update_time;
}
/* Take into account change of utilization of a child task group */
@@ -3295,8 +3319,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
set_tg_cfs_propagate(cfs_rq);
}
- decayed = __update_load_avg(now, cpu_of(rq_of(cfs_rq)), sa,
- scale_load_down(cfs_rq->load.weight), cfs_rq->curr != NULL, cfs_rq);
+ decayed = __update_load_avg_cfs_rq(now, cpu_of(rq_of(cfs_rq)), cfs_rq);
#ifndef CONFIG_64BIT
smp_wmb();
@@ -3328,11 +3351,8 @@ static inline void update_load_avg(struct sched_entity *se, int flags)
* Track task load average for carrying it to new CPU after migrated, and
* track group sched_entity load average for task_h_load calc in migration
*/
- if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD)) {
- __update_load_avg(now, cpu, &se->avg,
- se->on_rq * scale_load_down(se->load.weight),
- cfs_rq->curr == se, NULL);
- }
+ if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD))
+ __update_load_avg_se(now, cpu, cfs_rq, se);
decayed = update_cfs_rq_load_avg(now, cfs_rq, true);
decayed |= propagate_entity_load_avg(se);
@@ -3437,7 +3457,7 @@ void sync_entity_load_avg(struct sched_entity *se)
u64 last_update_time;
last_update_time = cfs_rq_last_update_time(cfs_rq);
- __update_load_avg(last_update_time, cpu_of(rq_of(cfs_rq)), &se->avg, 0, 0, NULL);
+ __update_load_avg_blocked_se(last_update_time, cpu_of(rq_of(cfs_rq)), se);
}
/*
--
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