diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2017-05-06 16:03:17 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-09-29 19:35:10 +0200 |
| commit | 7c80cfc99b7bfdc92cee26f8008859f326f4a37f (patch) | |
| tree | 019612e2f615a1fe00c41d7c88ce0cb2df76dcf4 /kernel/sched | |
| parent | 5ccba44ba118a5000cccc50076b0344632459779 (diff) | |
sched/fair: Clean up calc_cfs_shares()
For consistencies sake, we should have only a single reading of tg->shares.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/fair.c | 31 |
1 files changed, 12 insertions, 19 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 70ba32e08a23..048fbfb75523 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2694,9 +2694,12 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) #ifdef CONFIG_FAIR_GROUP_SCHED # ifdef CONFIG_SMP -static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) +static long calc_cfs_shares(struct cfs_rq *cfs_rq) { - long tg_weight, load, shares; + long tg_weight, tg_shares, load, shares; + struct task_group *tg = cfs_rq->tg; + + tg_shares = READ_ONCE(tg->shares); /* * This really should be: cfs_rq->avg.load_avg, but instead we use @@ -2711,7 +2714,7 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) tg_weight -= cfs_rq->tg_load_avg_contrib; tg_weight += load; - shares = (tg->shares * load); + shares = (tg_shares * load); if (tg_weight) shares /= tg_weight; @@ -2727,17 +2730,7 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) * case no task is runnable on a CPU MIN_SHARES=2 should be returned * instead of 0. */ - if (shares < MIN_SHARES) - shares = MIN_SHARES; - if (shares > tg->shares) - shares = tg->shares; - - return shares; -} -# else /* CONFIG_SMP */ -static inline long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) -{ - return tg->shares; + return clamp_t(long, shares, MIN_SHARES, tg_shares); } # endif /* CONFIG_SMP */ @@ -2762,7 +2755,6 @@ static inline int throttled_hierarchy(struct cfs_rq *cfs_rq); static void update_cfs_shares(struct sched_entity *se) { struct cfs_rq *cfs_rq = group_cfs_rq(se); - struct task_group *tg; long shares; if (!cfs_rq) @@ -2771,13 +2763,14 @@ static void update_cfs_shares(struct sched_entity *se) if (throttled_hierarchy(cfs_rq)) return; - tg = cfs_rq->tg; - #ifndef CONFIG_SMP - if (likely(se->load.weight == tg->shares)) + shares = READ_ONCE(cfs_rq->tg->shares); + + if (likely(se->load.weight == shares)) return; +#else + shares = calc_cfs_shares(cfs_rq); #endif - shares = calc_cfs_shares(cfs_rq, tg); reweight_entity(cfs_rq_of(se), se, shares); } |