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From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Mel Gorman <mgorman@techsingularity.net>,
	Rik van Riel <riel@surriel.com>,
	Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 13/19] mm/migrate: Use xchg instead of spinlock
Date: Mon,  4 Jun 2018 15:30:22 +0530	[thread overview]
Message-ID: <1528106428-19992-14-git-send-email-srikar@linux.vnet.ibm.com> (raw)
In-Reply-To: <1528106428-19992-1-git-send-email-srikar@linux.vnet.ibm.com>

Currently resetting the migrate rate limit is under a spinlock.
The spinlock will only serialize the migrate rate limiting and something
similar can actually be achieved by a simpler xchg.

Testcase       Time:         Min         Max         Avg      StdDev
numa01.sh      Real:      435.67      707.28      527.49       97.85
numa01.sh       Sys:       76.41      231.19      162.49       56.13
numa01.sh      User:    38247.36    59033.52    45129.31     7642.69
numa02.sh      Real:       60.35       62.09       61.09        0.69
numa02.sh       Sys:       15.01       30.20       20.64        5.56
numa02.sh      User:     5195.93     5294.82     5240.99       40.55
numa03.sh      Real:      752.04      919.89      836.81       63.29
numa03.sh       Sys:      115.10      133.35      125.46        7.78
numa03.sh      User:    58736.44    70084.26    65103.67     4416.10
numa04.sh      Real:      418.43      709.69      512.53      104.17
numa04.sh       Sys:      242.99      370.47      297.39       42.20
numa04.sh      User:    34916.14    48429.54    38955.65     4928.05
numa05.sh      Real:      379.27      434.05      403.70       17.79
numa05.sh       Sys:      145.94      344.50      268.72       68.53
numa05.sh      User:    32679.32    35449.75    33989.10      913.19

Testcase       Time:         Min         Max         Avg      StdDev 	 %Change
numa01.sh      Real:      490.04      774.86      596.26       96.46 	 -11.5%
numa01.sh       Sys:      151.52      242.88      184.82       31.71 	 -12.0%
numa01.sh      User:    41418.41    60844.59    48776.09     6564.27 	 -7.47%
numa02.sh      Real:       60.14       62.94       60.98        1.00 	 0.180%
numa02.sh       Sys:       16.11       30.77       21.20        5.28 	 -2.64%
numa02.sh      User:     5184.33     5311.09     5228.50       44.24 	 0.238%
numa03.sh      Real:      790.95      856.35      826.41       24.11 	 1.258%
numa03.sh       Sys:      114.93      118.85      117.05        1.63 	 7.184%
numa03.sh      User:    60990.99    64959.28    63470.43     1415.44 	 2.573%
numa04.sh      Real:      434.37      597.92      504.87       59.70 	 1.517%
numa04.sh       Sys:      237.63      397.40      289.74       55.98 	 2.640%
numa04.sh      User:    34854.87    41121.83    38572.52     2615.84 	 0.993%
numa05.sh      Real:      386.77      448.90      417.22       22.79 	 -3.24%
numa05.sh       Sys:      149.23      379.95      303.04       79.55 	 -11.3%
numa05.sh      User:    32951.76    35959.58    34562.18     1034.05 	 -1.65%

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
 include/linux/mmzone.h | 3 ---
 mm/migrate.c           | 8 +++-----
 mm/page_alloc.c        | 1 -
 3 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index b0767703..0dbe1d5 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -669,9 +669,6 @@ struct zonelist {
 	struct task_struct *kcompactd;
 #endif
 #ifdef CONFIG_NUMA_BALANCING
-	/* Lock serializing the migrate rate limiting window */
-	spinlock_t numabalancing_migrate_lock;
-
 	/* Rate limiting time interval */
 	unsigned long numabalancing_migrate_next_window;
 
diff --git a/mm/migrate.c b/mm/migrate.c
index 8c0af0f..1c55956 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1874,11 +1874,9 @@ static bool numamigrate_update_ratelimit(pg_data_t *pgdat,
 	 * all the time is being spent migrating!
 	 */
 	if (time_after(jiffies, pgdat->numabalancing_migrate_next_window)) {
-		spin_lock(&pgdat->numabalancing_migrate_lock);
-		pgdat->numabalancing_migrate_nr_pages = 0;
-		pgdat->numabalancing_migrate_next_window = jiffies +
-			msecs_to_jiffies(migrate_interval_millisecs);
-		spin_unlock(&pgdat->numabalancing_migrate_lock);
+		if (xchg(&pgdat->numabalancing_migrate_nr_pages, 0))
+			pgdat->numabalancing_migrate_next_window = jiffies +
+				msecs_to_jiffies(migrate_interval_millisecs);
 	}
 	if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages) {
 		trace_mm_numa_migrate_ratelimit(current, pgdat->node_id,
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4526643..464a25c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6208,7 +6208,6 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat)
 
 	pgdat_resize_init(pgdat);
 #ifdef CONFIG_NUMA_BALANCING
-	spin_lock_init(&pgdat->numabalancing_migrate_lock);
 	pgdat->numabalancing_migrate_nr_pages = 0;
 	pgdat->active_node_migrate = 0;
 	pgdat->numabalancing_migrate_next_window = jiffies;
-- 
1.8.3.1

  parent reply	other threads:[~2018-06-04 10:03 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-04 10:00 [PATCH 00/19] Fixes for sched/numa_balancing Srikar Dronamraju
2018-06-04 10:00 ` [PATCH 01/19] sched/numa: Remove redundant field Srikar Dronamraju
2018-06-04 14:53   ` Rik van Riel
2018-06-05  8:41   ` Mel Gorman
2018-06-04 10:00 ` [PATCH 02/19] sched/numa: Evaluate move once per node Srikar Dronamraju
2018-06-04 14:51   ` Rik van Riel
2018-06-04 15:45     ` Srikar Dronamraju
2018-06-04 10:00 ` [PATCH 03/19] sched/numa: Simplify load_too_imbalanced Srikar Dronamraju
2018-06-04 14:57   ` Rik van Riel
2018-06-05  8:46   ` Mel Gorman
2018-06-04 10:00 ` [PATCH 04/19] sched/numa: Set preferred_node based on best_cpu Srikar Dronamraju
2018-06-04 12:18   ` Peter Zijlstra
2018-06-04 12:53     ` Srikar Dronamraju
2018-06-04 12:23   ` Peter Zijlstra
2018-06-04 12:59     ` Srikar Dronamraju
2018-06-04 13:39       ` Peter Zijlstra
2018-06-04 13:48         ` Srikar Dronamraju
2018-06-04 14:37       ` Rik van Riel
2018-06-04 15:56         ` Srikar Dronamraju
2018-06-04 10:00 ` [PATCH 05/19] sched/numa: Use task faults only if numa_group is not yet setup Srikar Dronamraju
2018-06-04 12:24   ` Peter Zijlstra
2018-06-04 13:09     ` Srikar Dronamraju
2018-06-04 10:00 ` [PATCH 06/19] sched/debug: Reverse the order of printing faults Srikar Dronamraju
2018-06-04 16:28   ` Rik van Riel
2018-06-05  8:50   ` Mel Gorman
2018-06-04 10:00 ` [PATCH 07/19] sched/numa: Skip nodes that are at hoplimit Srikar Dronamraju
2018-06-04 16:27   ` Rik van Riel
2018-06-05  8:50   ` Mel Gorman
2018-06-04 10:00 ` [PATCH 08/19] sched/numa: Remove unused task_capacity from numa_stats Srikar Dronamraju
2018-06-04 16:28   ` Rik van Riel
2018-06-05  8:57   ` Mel Gorman
2018-06-04 10:00 ` [PATCH 09/19] sched/numa: Modify migrate_swap to accept additional params Srikar Dronamraju
2018-06-04 17:00   ` Rik van Riel
2018-06-05  8:58   ` Mel Gorman
2018-06-04 10:00 ` [PATCH 10/19] sched/numa: Stop multiple tasks from moving to the cpu at the same time Srikar Dronamraju
2018-06-04 17:57   ` Rik van Riel
2018-06-05  9:51   ` Mel Gorman
2018-06-04 10:00 ` [PATCH 11/19] sched/numa: Restrict migrating in parallel to the same node Srikar Dronamraju
2018-06-04 17:59   ` Rik van Riel
2018-06-05  9:53   ` Mel Gorman
2018-06-06 12:58     ` Srikar Dronamraju
2018-06-04 10:00 ` [PATCH 12/19] sched:numa Remove numa_has_capacity Srikar Dronamraju
2018-06-04 18:07   ` Rik van Riel
2018-06-04 10:00 ` Srikar Dronamraju [this message]
2018-06-04 18:22   ` [PATCH 13/19] mm/migrate: Use xchg instead of spinlock Rik van Riel
2018-06-04 19:28   ` Peter Zijlstra
2018-06-05  7:24     ` Srikar Dronamraju
2018-06-05  8:16       ` Peter Zijlstra
2018-06-04 10:00 ` [PATCH 14/19] sched/numa: Updation of scan period need not be in lock Srikar Dronamraju
2018-06-04 18:24   ` Rik van Riel
2018-06-04 10:00 ` [PATCH 15/19] sched/numa: Use group_weights to identify if migration degrades locality Srikar Dronamraju
2018-06-04 18:56   ` Rik van Riel
2018-06-04 10:00 ` [PATCH 16/19] sched/numa: Detect if node actively handling migration Srikar Dronamraju
2018-06-04 20:05   ` Rik van Riel
2018-06-05  3:56     ` Srikar Dronamraju
2018-06-05 13:07       ` Rik van Riel
2018-06-06 12:55         ` Srikar Dronamraju
2018-06-06 13:55           ` Rik van Riel
2018-06-06 15:32             ` Srikar Dronamraju
2018-06-06 17:06               ` Rik van Riel
2018-06-04 10:00 ` [PATCH 17/19] sched/numa: Pass destination cpu as a parameter to migrate_task_rq Srikar Dronamraju
2018-06-04 10:00 ` [PATCH 18/19] sched/numa: Reset scan rate whenever task moves across nodes Srikar Dronamraju
2018-06-04 20:08   ` Rik van Riel
2018-06-05  9:58   ` Mel Gorman
2018-06-06 13:47     ` Srikar Dronamraju
2018-06-04 10:00 ` [PATCH 19/19] sched/numa: Move task_placement closer to numa_migrate_preferred Srikar Dronamraju

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