linux-kernel - [RFC patch 2/4] sched/tg: use 'unsigned long' for load variable in task group

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Message-Id: <1370590169-24804-3-git-send-email-alex.shi@intel.com>
Date:	Fri,  7 Jun 2013 15:29:27 +0800
From:	Alex Shi <alex.shi@...el.com>
To:	mingo@...hat.com, peterz@...radead.org, tglx@...utronix.de,
	akpm@...ux-foundation.org, bp@...en8.de, pjt@...gle.com,
	namhyung@...nel.org, efault@....de, morten.rasmussen@....com
Cc:	vincent.guittot@...aro.org, preeti@...ux.vnet.ibm.com,
	viresh.kumar@...aro.org, linux-kernel@...r.kernel.org,
	alex.shi@...el.com, mgorman@...e.de, riel@...hat.com,
	wangyun@...ux.vnet.ibm.com, Jason Low <jason.low2@...com>
Subject: [RFC patch 2/4] sched/tg: use 'unsigned long' for load variable in task group

Since tg->load_avg is smaller than tg->load_weight, we don't need a
atomic64_t variable for load_avg in 32 bit machine.
The same reason for cfs_rq->tg_load_contrib.

The atomic_long_t/unsigned long variable type are more efficient and
convenience for them.

Signed-off-by: Alex Shi <alex.shi@...el.com>
---
 kernel/sched/debug.c |  6 +++---
 kernel/sched/fair.c  | 12 ++++++------
 kernel/sched/sched.h |  4 ++--
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 160afdc..d803989 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -215,9 +215,9 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 			cfs_rq->runnable_load_avg);
 	SEQ_printf(m, "  .%-30s: %ld\n", "blocked_load_avg",
 			cfs_rq->blocked_load_avg);
-	SEQ_printf(m, "  .%-30s: %lld\n", "tg_load_avg",
-			(unsigned long long)atomic64_read(&cfs_rq->tg->load_avg));
-	SEQ_printf(m, "  .%-30s: %lld\n", "tg_load_contrib",
+	SEQ_printf(m, "  .%-30s: %ld\n", "tg_load_avg",
+			atomic_long_read(&cfs_rq->tg->load_avg));
+	SEQ_printf(m, "  .%-30s: %ld\n", "tg_load_contrib",
 			cfs_rq->tg_load_contrib);
 	SEQ_printf(m, "  .%-30s: %d\n", "tg_runnable_contrib",
 			cfs_rq->tg_runnable_contrib);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 985d47e..30fb7dc 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1075,7 +1075,7 @@ static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq)
 	 * to gain a more accurate current total weight. See
 	 * update_cfs_rq_load_contribution().
 	 */
-	tg_weight = atomic64_read(&tg->load_avg);
+	tg_weight = atomic_long_read(&tg->load_avg);
 	tg_weight -= cfs_rq->tg_load_contrib;
 	tg_weight += cfs_rq->load.weight;
 
@@ -1356,13 +1356,13 @@ static inline void __update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq,
 						 int force_update)
 {
 	struct task_group *tg = cfs_rq->tg;
-	s64 tg_contrib;
+	long tg_contrib;
 
 	tg_contrib = cfs_rq->runnable_load_avg;
 	tg_contrib -= cfs_rq->tg_load_contrib;
 
-	if (force_update || abs64(tg_contrib) > cfs_rq->tg_load_contrib / 8) {
-		atomic64_add(tg_contrib, &tg->load_avg);
+	if (force_update || abs(tg_contrib) > cfs_rq->tg_load_contrib / 8) {
+		atomic_long_add(tg_contrib, &tg->load_avg);
 		cfs_rq->tg_load_contrib += tg_contrib;
 	}
 }
@@ -1397,8 +1397,8 @@ static inline void __update_group_entity_contrib(struct sched_entity *se)
 	u64 contrib;
 
 	contrib = cfs_rq->tg_load_contrib * tg->shares;
-	se->avg.load_avg_contrib = div64_u64(contrib,
-					     atomic64_read(&tg->load_avg) + 1);
+	se->avg.load_avg_contrib = div_u64(contrib,
+				     atomic_long_read(&tg->load_avg) + 1);
 
 	/*
 	 * For group entities we need to compute a correction term in the case
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 5a80943..1bfa91a 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -150,7 +150,7 @@ struct task_group {
 
 	atomic_t load_weight;
 #ifdef	CONFIG_SMP
-	atomic64_t load_avg;
+	atomic_long_t load_avg;
 	atomic_t runnable_avg;
 #endif
 #endif
@@ -284,7 +284,7 @@ struct cfs_rq {
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	/* Required to track per-cpu representation of a task_group */
 	u32 tg_runnable_contrib;
-	u64 tg_load_contrib;
+	unsigned long tg_load_contrib;
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
 	/*
-- 
1.7.12

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