From: Mel Gorman <mgorman@techsingularity.net>
To: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Rik van Riel <riel@surriel.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH v2 13/19] mm/migrate: Use xchg instead of spinlock
Date: Thu, 21 Jun 2018 10:51:12 +0100 [thread overview]
Message-ID: <20180621095111.md7m5jhxxoswnykf@techsingularity.net> (raw)
In-Reply-To: <1529514181-9842-14-git-send-email-srikar@linux.vnet.ibm.com>
On Wed, Jun 20, 2018 at 10:32:54PM +0530, Srikar Dronamraju wrote:
> 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.
>
> Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
> JVMS LAST_PATCH WITH_PATCH %CHANGE
> 16 25804.1 25355.9 -1.73
> 1 73413 72812 -0.81
>
> Running SPECjbb2005 on a 16 node machine and comparing bops/JVM
> JVMS LAST_PATCH WITH_PATCH %CHANGE
> 8 101748 110199 8.30
> 1 170818 176303 3.21
>
> (numbers from v1 based on v4.17-rc5)
> 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>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
However, I'm actively considering removing rate limiting entirely. It
has been reported elsewhere that it was a limiting factor for some
workloads. When it was introduced, it was to avoid worst-case migration
storms but I believe that those ping-pong style problems should now be
ok.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2018-06-21 9:51 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-20 17:02 [PATCH v2 00/19] Fixes for sched/numa_balancing Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 01/19] sched/numa: Remove redundant field Srikar Dronamraju
2018-07-25 14:23 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 02/19] sched/numa: Evaluate move once per node Srikar Dronamraju
2018-06-21 9:06 ` Mel Gorman
2018-07-25 14:24 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 03/19] sched/numa: Simplify load_too_imbalanced Srikar Dronamraju
2018-07-25 14:24 ` [tip:sched/core] sched/numa: Simplify load_too_imbalanced() tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 04/19] sched/numa: Set preferred_node based on best_cpu Srikar Dronamraju
2018-06-21 9:17 ` Mel Gorman
2018-07-25 14:25 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 05/19] sched/numa: Use task faults only if numa_group is not yet setup Srikar Dronamraju
2018-06-21 9:38 ` Mel Gorman
2018-07-25 14:25 ` [tip:sched/core] sched/numa: Use task faults only if numa_group is not yet set up tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 06/19] sched/debug: Reverse the order of printing faults Srikar Dronamraju
2018-07-25 14:26 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 07/19] sched/numa: Skip nodes that are at hoplimit Srikar Dronamraju
2018-07-25 14:27 ` [tip:sched/core] sched/numa: Skip nodes that are at 'hoplimit' tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 08/19] sched/numa: Remove unused task_capacity from numa_stats Srikar Dronamraju
2018-07-25 14:27 ` [tip:sched/core] sched/numa: Remove unused task_capacity from 'struct numa_stats' tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 09/19] sched/numa: Modify migrate_swap to accept additional params Srikar Dronamraju
2018-07-25 14:28 ` [tip:sched/core] sched/numa: Modify migrate_swap() to accept additional parameters tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 10/19] sched/numa: Stop multiple tasks from moving to the cpu at the same time Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 11/19] sched/numa: Restrict migrating in parallel to the same node Srikar Dronamraju
2018-07-23 10:38 ` Peter Zijlstra
2018-07-23 11:16 ` Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 12/19] sched/numa: Remove numa_has_capacity Srikar Dronamraju
2018-07-25 14:28 ` [tip:sched/core] sched/numa: Remove numa_has_capacity() tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 13/19] mm/migrate: Use xchg instead of spinlock Srikar Dronamraju
2018-06-21 9:51 ` Mel Gorman [this message]
2018-07-23 10:54 ` Peter Zijlstra
2018-07-23 11:20 ` Srikar Dronamraju
2018-07-23 14:04 ` Peter Zijlstra
2018-06-20 17:02 ` [PATCH v2 14/19] sched/numa: Updation of scan period need not be in lock Srikar Dronamraju
2018-06-21 9:51 ` Mel Gorman
2018-07-25 14:29 ` [tip:sched/core] sched/numa: Update the scan period without holding the numa_group lock tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 15/19] sched/numa: Use group_weights to identify if migration degrades locality Srikar Dronamraju
2018-07-25 14:29 ` [tip:sched/core] " tip-bot for Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 16/19] sched/numa: Detect if node actively handling migration Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 17/19] sched/numa: Pass destination cpu as a parameter to migrate_task_rq Srikar Dronamraju
2018-06-20 17:02 ` [PATCH v2 18/19] sched/numa: Reset scan rate whenever task moves across nodes Srikar Dronamraju
2018-06-21 10:05 ` Mel Gorman
2018-07-04 11:19 ` Srikar Dronamraju
2018-06-20 17:03 ` [PATCH v2 19/19] sched/numa: Move task_placement closer to numa_migrate_preferred Srikar Dronamraju
2018-06-21 10:06 ` Mel Gorman
2018-07-25 14:30 ` [tip:sched/core] sched/numa: Move task_numa_placement() closer to numa_migrate_preferred() tip-bot for Srikar Dronamraju
2018-06-20 17:03 ` [PATCH v2 00/19] Fixes for sched/numa_balancing Srikar Dronamraju
2018-07-23 13:57 ` Peter Zijlstra
2018-07-23 15:09 ` Srikar Dronamraju
2018-07-23 15:21 ` Peter Zijlstra
2018-07-23 16:29 ` Srikar Dronamraju
2018-07-23 16:47 ` Peter Zijlstra
2018-07-23 15:33 ` Rik van Riel
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