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From: Nikhil Rao <ncrao@google.com>
To: Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <peterz@infradead.org>,
	Mike Galbraith <efault@gmx.de>
Cc: linux-kernel@vger.kernel.org,
	"Nikunj A. Dadhania" <nikunj@linux.vnet.ibm.com>,
	Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
	Stephan Barwolf <stephan.baerwolf@tu-ilmenau.de>,
	Nikhil Rao <ncrao@google.com>
Subject: [PATCH v1 19/19] sched: convert atomic ops in shares update to use atomic64_t ops
Date: Sun,  1 May 2011 18:19:17 -0700	[thread overview]
Message-ID: <1304299157-25769-20-git-send-email-ncrao@google.com> (raw)
In-Reply-To: <1304299157-25769-1-git-send-email-ncrao@google.com>

Convert uses of atomic_t to atomic64_t in shares update calculations. Total
task weight in a tg can overflow the atomic type on 32-bit systems.

Signed-off-by: Nikhil Rao <ncrao@google.com>
---
 kernel/sched.c       |    2 +-
 kernel/sched_debug.c |    4 ++--
 kernel/sched_fair.c  |    8 +++-----
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index e131225..af26b3e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -255,7 +255,7 @@ struct task_group {
 	struct cfs_rq **cfs_rq;
 	unsigned long shares;
 
-	atomic_t load_weight;
+	atomic64_t load_weight;
 #endif
 
 #ifdef CONFIG_RT_GROUP_SCHED
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index b809651..2d0fff9 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -210,8 +210,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 			SPLIT_NS(cfs_rq->load_period));
 	SEQ_printf(m, "  .%-30s: %lld\n", "load_contrib",
 			cfs_rq->load_contribution);
-	SEQ_printf(m, "  .%-30s: %d\n", "load_tg",
-			atomic_read(&cfs_rq->tg->load_weight));
+	SEQ_printf(m, "  .%-30s: %ld\n", "load_tg",
+			atomic64_read(&cfs_rq->tg->load_weight));
 #endif
 
 	print_cfs_group_stats(m, cpu, cfs_rq->tg);
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 3f56410..0152410 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -714,8 +714,7 @@ static void update_cfs_rq_load_contribution(struct cfs_rq *cfs_rq,
 	load_avg -= cfs_rq->load_contribution;
 
 	if (global_update || abs(load_avg) > cfs_rq->load_contribution / 8) {
-		/* TODO: fix atomics for 64-bit additions */
-		atomic_add(load_avg, &tg->load_weight);
+		atomic64_add(load_avg, &tg->load_weight);
 		cfs_rq->load_contribution += load_avg;
 	}
 }
@@ -779,8 +778,7 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
 
 	load = cfs_rq->load.weight;
 
-	/* TODO: fixup atomics to handle u64 in 32-bit */
-	load_weight = atomic_read(&tg->load_weight);
+	load_weight = atomic64_read(&tg->load_weight);
 	load_weight += load;
 	load_weight -= cfs_rq->load_contribution;
 
@@ -1409,7 +1407,7 @@ static s64 effective_load(struct task_group *tg, int cpu, s64 wl, s64 wg)
 		w = se->my_q->load.weight;
 
 		/* use this cpu's instantaneous contribution */
-		lw = atomic_read(&tg->load_weight);
+		lw = atomic64_read(&tg->load_weight);
 		lw -= se->my_q->load_contribution;
 		lw += w + wg;
 
-- 
1.7.3.1


  parent reply	other threads:[~2011-05-02  1:23 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-02  1:18 [PATCH v1 00/19] Increase resolution of load weights Nikhil Rao
2011-05-02  1:18 ` [PATCH v1 01/19] sched: introduce SCHED_POWER_SCALE to scale cpu_power calculations Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 02/19] sched: increase SCHED_LOAD_SCALE resolution Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 03/19] sched: use u64 for load_weight fields Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 04/19] sched: update cpu_load to be u64 Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 05/19] sched: update this_cpu_load() to return u64 value Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 06/19] sched: update source_load(), target_load() and weighted_cpuload() to use u64 Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 07/19] sched: update find_idlest_cpu() to use u64 for load Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 08/19] sched: update find_idlest_group() to use u64 Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 09/19] sched: update division in cpu_avg_load_per_task to use div_u64 Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 10/19] sched: update wake_affine path to use u64, s64 for weights Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 11/19] sched: update update_sg_lb_stats() to use u64 Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 12/19] sched: Update update_sd_lb_stats() " Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 13/19] sched: update f_b_g() to use u64 for weights Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 14/19] sched: change type of imbalance to be u64 Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 15/19] sched: update h_load to use u64 Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 16/19] sched: update move_task() and helper functions to use u64 for weights Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 17/19] sched: update f_b_q() to use u64 for weighted cpuload Nikhil Rao
2011-05-02  1:19 ` [PATCH v1 18/19] sched: update shares distribution to use u64 Nikhil Rao
2011-05-02  1:19 ` Nikhil Rao [this message]
2011-05-02  6:14 ` [PATCH v1 00/19] Increase resolution of load weights Ingo Molnar
2011-05-04  0:58   ` Nikhil Rao
2011-05-04  1:07     ` Nikhil Rao
2011-05-04 11:13     ` Ingo Molnar
2011-05-06  1:29       ` Nikhil Rao
2011-05-06  6:59         ` Ingo Molnar
2011-05-11  0:14           ` Nikhil Rao
2011-05-11  6:59             ` Ingo Molnar
2011-05-12  8:56               ` Nikhil Rao
2011-05-12 10:55                 ` Ingo Molnar
2011-05-12 18:44                   ` Nikhil Rao
2011-05-12  9:08         ` Peter Zijlstra
2011-05-12 17:30           ` Nikhil Rao
2011-05-13  7:19             ` Peter Zijlstra

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