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From: Dave Chinner <david@fromorbit.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>,
	Linux Kernel List <linux-kernel@vger.kernel.org>,
	linux-mm@kvack.org, Rik van Riel <riel@redhat.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Minchan Kim <minchan.kim@gmail.com>,
	Christoph Lameter <cl@linux-foundation.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	Wu Fengguang <fengguang.wu@intel.com>,
	David Rientjes <rientjes@google.com>
Subject: Re: [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails
Date: Sat, 4 Sep 2010 17:58:40 +1000	[thread overview]
Message-ID: <20100904075840.GE705@dastard> (raw)
In-Reply-To: <20100903202101.f937b0bb.akpm@linux-foundation.org>

On Fri, Sep 03, 2010 at 08:21:01PM -0700, Andrew Morton wrote:
> On Sat, 4 Sep 2010 12:25:45 +1000 Dave Chinner <david@fromorbit.com> wrote:
> 
> > Still, given the improvements in performance from this patchset,
> > I'd say inclusion is a no-braniner....
> 
> OK, thanks.
> 
> It'd be interesting to check the IPI frequency with and without -
> /proc/interrupts "CAL" field.  Presumably it went down a lot.

Maybe I suspected you would ask for this. I happened to dump
/proc/interrupts after the livelock run finished, so you're in
luck :)

The lines below are:

before: before running the single 50M inode create workload
after: the numbers after the run completes
livelock: the numbers after two runs with a livelock in the second

Vanilla 2.6.36-rc3:

before:      561   350   614   282   559   335   365   363
after:	   10472 10473 10544 10681  9818 10837 10187  9923

.36-rc3 With patchset:

before:      452   426   441   337   748   321   498   357
after:      9463  9112  8671  8830  9391  8684  9768  8971

The numbers aren't that different - roughly 10% lower on average
with the patchset. I will state that vanilla kernel runs I ijust did
had noticably more consistent performance than the previous results
I had acheived, so perhaps it wasn't triggering the livelock
conditions as effectively this time through.

And finally:

livelock:  59458 58367 58559 59493 59614 57970 59060 58207

So the livelock case tends to indicate roughly 40,000 more IPI
interrupts per CPU occurred.  The livelock occurred for close to 5
minutes, so that's roughly 130 IPIs per second per CPU....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david@fromorbit.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>,
	Linux Kernel List <linux-kernel@vger.kernel.org>,
	linux-mm@kvack.org, Rik van Riel <riel@redhat.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Minchan Kim <minchan.kim@gmail.com>,
	Christoph Lameter <cl@linux-foundation.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
	Wu Fengguang <fengguang.wu@intel.com>,
	David Rientjes <rientjes@google.com>
Subject: Re: [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails
Date: Sat, 4 Sep 2010 17:58:40 +1000	[thread overview]
Message-ID: <20100904075840.GE705@dastard> (raw)
In-Reply-To: <20100903202101.f937b0bb.akpm@linux-foundation.org>

On Fri, Sep 03, 2010 at 08:21:01PM -0700, Andrew Morton wrote:
> On Sat, 4 Sep 2010 12:25:45 +1000 Dave Chinner <david@fromorbit.com> wrote:
> 
> > Still, given the improvements in performance from this patchset,
> > I'd say inclusion is a no-braniner....
> 
> OK, thanks.
> 
> It'd be interesting to check the IPI frequency with and without -
> /proc/interrupts "CAL" field.  Presumably it went down a lot.

Maybe I suspected you would ask for this. I happened to dump
/proc/interrupts after the livelock run finished, so you're in
luck :)

The lines below are:

before: before running the single 50M inode create workload
after: the numbers after the run completes
livelock: the numbers after two runs with a livelock in the second

Vanilla 2.6.36-rc3:

before:      561   350   614   282   559   335   365   363
after:	   10472 10473 10544 10681  9818 10837 10187  9923

.36-rc3 With patchset:

before:      452   426   441   337   748   321   498   357
after:      9463  9112  8671  8830  9391  8684  9768  8971

The numbers aren't that different - roughly 10% lower on average
with the patchset. I will state that vanilla kernel runs I ijust did
had noticably more consistent performance than the previous results
I had acheived, so perhaps it wasn't triggering the livelock
conditions as effectively this time through.

And finally:

livelock:  59458 58367 58559 59493 59614 57970 59060 58207

So the livelock case tends to indicate roughly 40,000 more IPI
interrupts per CPU occurred.  The livelock occurred for close to 5
minutes, so that's roughly 130 IPIs per second per CPU....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

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  reply	other threads:[~2010-09-04  8:00 UTC|newest]

Thread overview: 104+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-03  9:08 [PATCH 0/3] Reduce watermark-related problems with the per-cpu allocator V4 Mel Gorman
2010-09-03  9:08 ` Mel Gorman
2010-09-03  9:08 ` [PATCH 1/3] mm: page allocator: Update free page counters after pages are placed on the free list Mel Gorman
2010-09-03  9:08   ` Mel Gorman
2010-09-03 22:38   ` Andrew Morton
2010-09-03 22:38     ` Andrew Morton
2010-09-05 18:06     ` Mel Gorman
2010-09-05 18:06       ` Mel Gorman
2010-09-03  9:08 ` [PATCH 2/3] mm: page allocator: Calculate a better estimate of NR_FREE_PAGES when memory is low and kswapd is awake Mel Gorman
2010-09-03  9:08   ` Mel Gorman
2010-09-03 22:55   ` Andrew Morton
2010-09-03 22:55     ` Andrew Morton
2010-09-03 23:17     ` Christoph Lameter
2010-09-03 23:17       ` Christoph Lameter
2010-09-03 23:28       ` Andrew Morton
2010-09-03 23:28         ` Andrew Morton
2010-09-04  0:54         ` Christoph Lameter
2010-09-04  0:54           ` Christoph Lameter
2010-09-05 18:12     ` Mel Gorman
2010-09-05 18:12       ` Mel Gorman
2010-09-03  9:08 ` [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails Mel Gorman
2010-09-03  9:08   ` Mel Gorman
2010-09-03 23:00   ` Andrew Morton
2010-09-03 23:00     ` Andrew Morton
2010-09-04  2:25     ` Dave Chinner
2010-09-04  2:25       ` Dave Chinner
2010-09-04  3:21       ` Andrew Morton
2010-09-04  3:21         ` Andrew Morton
2010-09-04  7:58         ` Dave Chinner [this message]
2010-09-04  7:58           ` Dave Chinner
2010-09-04  8:14           ` Dave Chinner
2010-09-04  8:14             ` Dave Chinner
     [not found]             ` <20100905015400.GA10714@localhost>
     [not found]               ` <20100905021555.GG705@dastard>
     [not found]                 ` <20100905060539.GA17450@localhost>
     [not found]                   ` <20100905131447.GJ705@dastard>
2010-09-05 13:45                     ` Wu Fengguang
2010-09-05 13:45                       ` Wu Fengguang
2010-09-05 23:33                       ` Dave Chinner
2010-09-05 23:33                         ` Dave Chinner
2010-09-06  4:02                       ` Dave Chinner
2010-09-06  4:02                         ` Dave Chinner
2010-09-06  8:40                         ` Mel Gorman
2010-09-06  8:40                           ` Mel Gorman
2010-09-06 21:50                           ` Dave Chinner
2010-09-06 21:50                             ` Dave Chinner
2010-09-08  8:49                             ` Dave Chinner
2010-09-08  8:49                               ` Dave Chinner
2010-09-09 12:39                               ` Mel Gorman
2010-09-09 12:39                                 ` Mel Gorman
2010-09-10  6:17                                 ` Dave Chinner
2010-09-10  6:17                                   ` Dave Chinner
2010-09-07 14:23                         ` Christoph Lameter
2010-09-07 14:23                           ` Christoph Lameter
2010-09-08  2:13                           ` Wu Fengguang
2010-09-08  2:13                             ` Wu Fengguang
2010-09-04  3:23       ` Wu Fengguang
2010-09-04  3:23         ` Wu Fengguang
2010-09-04  3:59         ` Andrew Morton
2010-09-04  3:59           ` Andrew Morton
2010-09-04  4:37           ` Wu Fengguang
2010-09-04  4:37             ` Wu Fengguang
2010-09-05 18:22       ` Mel Gorman
2010-09-05 18:22         ` Mel Gorman
2010-09-05 18:14     ` Mel Gorman
2010-09-05 18:14       ` Mel Gorman
2010-09-08  7:43   ` KOSAKI Motohiro
2010-09-08  7:43     ` KOSAKI Motohiro
2010-09-08 20:05     ` Christoph Lameter
2010-09-08 20:05       ` Christoph Lameter
2010-09-09 12:41     ` Mel Gorman
2010-09-09 12:41       ` Mel Gorman
2010-09-09 13:45       ` Christoph Lameter
2010-09-09 13:45         ` Christoph Lameter
2010-09-09 13:55         ` Mel Gorman
2010-09-09 13:55           ` Mel Gorman
2010-09-09 14:32           ` Christoph Lameter
2010-09-09 14:32             ` Christoph Lameter
2010-09-09 15:05             ` Mel Gorman
2010-09-09 15:05               ` Mel Gorman
2010-09-10  2:56               ` KOSAKI Motohiro
2010-09-10  2:56                 ` KOSAKI Motohiro
2010-09-03 23:05 ` [PATCH 0/3] Reduce watermark-related problems with the per-cpu allocator V4 Andrew Morton
2010-09-03 23:05   ` Andrew Morton
2010-09-21 11:17   ` Mel Gorman
2010-09-21 11:17     ` Mel Gorman
2010-09-21 12:58     ` [stable] " Greg KH
2010-09-21 12:58       ` Greg KH
2010-09-21 14:23       ` Mel Gorman
2010-09-21 14:23         ` Mel Gorman
2010-09-23 18:49         ` Greg KH
2010-09-23 18:49           ` Greg KH
2010-09-24  9:14           ` Mel Gorman
2010-09-24  9:14             ` Mel Gorman
  -- strict thread matches above, loose matches on Subject: below --
2010-08-31 17:37 [PATCH 0/3] Reduce watermark-related problems with the per-cpu allocator V3 Mel Gorman
2010-08-31 17:37 ` [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails Mel Gorman
2010-08-31 17:37   ` Mel Gorman
2010-08-31 18:26   ` Christoph Lameter
2010-08-31 18:26     ` Christoph Lameter
2010-08-23  8:00 [PATCH 0/3] Reduce watermark-related problems with the per-cpu allocator V2 Mel Gorman
2010-08-23  8:00 ` [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails Mel Gorman
2010-08-23  8:00   ` Mel Gorman
2010-08-23 23:17   ` KOSAKI Motohiro
2010-08-23 23:17     ` KOSAKI Motohiro
2010-08-16  9:42 [RFC PATCH 0/3] Reduce watermark-related problems with the per-cpu allocator Mel Gorman
2010-08-16  9:42 ` [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails Mel Gorman
2010-08-16 14:50   ` Rik van Riel
2010-08-17  2:57   ` Minchan Kim
2010-08-18  3:02   ` KAMEZAWA Hiroyuki
2010-08-19 14:47   ` Minchan Kim
2010-08-19 15:10     ` Mel Gorman

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