From: Satoru Moriya <satoru.moriya@hds.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"lwoodman@redhat.com" <lwoodman@redhat.com>,
Seiji Aguchi <saguchi@redhat.com>,
"hughd@google.com" <hughd@google.com>,
"hannes@cmpxchg.org" <hannes@cmpxchg.org>
Subject: Re: [PATCH -v2 -mm] add extra free kbytes tunable
Date: Wed, 14 Sep 2011 23:33:34 -0400 [thread overview]
Message-ID: <65795E11DBF1E645A09CEC7EAEE94B9CAFE00221@USINDEVS02.corp.hds.com> (raw)
In-Reply-To: <E1FA588BC672D846BDBB452FCA1E308C2389B4@USINDEVS02.corp.hds.com>
On 09/02/2011 12:31 PM, Satoru Moriya wrote:
> On 09/01/2011 05:58 PM, Andrew Morton wrote:
>> On Thu, 1 Sep 2011 15:26:50 -0400
>> Rik van Riel <riel@redhat.com> wrote:
> Anyway, now I'm testing this patch and will report a test result later.
Sorry for late reply. Here is my test result.
I ran some sample workloads and measure memory allocation latency
(latency of __alloc_page_nodemask()).
The test is like following:
- CPU: 1 socket, 4 core
- Memory: 4GB
- Background load:
$ dd if=/dev/zero of=/tmp/tmp1
$ dd if=/dev/zero of=/tmp/tmp2
$ dd if=/dev/zero of=/tmp/tmp3
- Main load:
$ mapped-file-stream 1 $((1024 * 1024 * 640)) --(*)
(*) This is made by Johannes Weiner
https://lkml.org/lkml/2010/8/30/226
It allocates/access 640MByte memory at a burst.
The result is follwoing:
| | extra |
| default | kbytes |
--------------------------------------------------------------
min_free_kbytes | 8113 | 8113 |
extra_free_kbytes | 0 | 640*1024 | (KB)
--------------------------------------------------------------
worst latency | 517.762 | 20.775 | (usec)
--------------------------------------------------------------
vmstat result | | |
nr_vmscan_write | 0 | 0 |
pgsteal_dma | 0 | 0 |
pgsteal_dma32 | 143667 | 144882 |
pgsteal_normal | 31486 | 27001 |
pgsteal_movable | 0 | 0 |
pgscan_kswapd_dma | 0 | 0 |
pgscan_kswapd_dma32 | 138617 | 156351 |
pgscan_kswapd_normal | 30593 | 27955 |
pgscan_kswapd_movable | 0 | 0 |
pgscan_direct_dma | 0 | 0 |
pgscan_direct_dma32 | 5050 | 0 |
pgscan_direct_normal | 896 | 0 |
pgscan_direct_movable | 0 | 0 |
kswapd_steal | 169207 | 171883 |
kswapd_inodesteal | 0 | 0 |
kswapd_low_wmark_hit_quickly | 43 | 45 |
kswapd_high_wmark_hit_quickly | 1 | 0 |
allocstall | 32 | 0 |
As you can see, in the default case there were 32 direct reclaim (allocstall)
and its worst latency was 517.762 usecs. This value may be larger if
a process would sleep or issue I/O in the direct reclaim path. OTOH,
ii the other case where I add extra free bytes, there were no direct
reclaim and its worst latency was 20.775 usecs.
In this test case, we can avoid direct reclaim and keep a latency low.
Tested-by: Satoru Moriya <satoru.moriya@hds.com>
WARNING: multiple messages have this Message-ID (diff)
From: Satoru Moriya <satoru.moriya@hds.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"lwoodman@redhat.com" <lwoodman@redhat.com>,
Seiji Aguchi <saguchi@redhat.com>,
"hughd@google.com" <hughd@google.com>,
"hannes@cmpxchg.org" <hannes@cmpxchg.org>
Subject: Re: [PATCH -v2 -mm] add extra free kbytes tunable
Date: Wed, 14 Sep 2011 23:33:34 -0400 [thread overview]
Message-ID: <65795E11DBF1E645A09CEC7EAEE94B9CAFE00221@USINDEVS02.corp.hds.com> (raw)
In-Reply-To: <E1FA588BC672D846BDBB452FCA1E308C2389B4@USINDEVS02.corp.hds.com>
On 09/02/2011 12:31 PM, Satoru Moriya wrote:
> On 09/01/2011 05:58 PM, Andrew Morton wrote:
>> On Thu, 1 Sep 2011 15:26:50 -0400
>> Rik van Riel <riel@redhat.com> wrote:
> Anyway, now I'm testing this patch and will report a test result later.
Sorry for late reply. Here is my test result.
I ran some sample workloads and measure memory allocation latency
(latency of __alloc_page_nodemask()).
The test is like following:
- CPU: 1 socket, 4 core
- Memory: 4GB
- Background load:
$ dd if=/dev/zero of=/tmp/tmp1
$ dd if=/dev/zero of=/tmp/tmp2
$ dd if=/dev/zero of=/tmp/tmp3
- Main load:
$ mapped-file-stream 1 $((1024 * 1024 * 640)) --(*)
(*) This is made by Johannes Weiner
https://lkml.org/lkml/2010/8/30/226
It allocates/access 640MByte memory at a burst.
The result is follwoing:
| | extra |
| default | kbytes |
--------------------------------------------------------------
min_free_kbytes | 8113 | 8113 |
extra_free_kbytes | 0 | 640*1024 | (KB)
--------------------------------------------------------------
worst latency | 517.762 | 20.775 | (usec)
--------------------------------------------------------------
vmstat result | | |
nr_vmscan_write | 0 | 0 |
pgsteal_dma | 0 | 0 |
pgsteal_dma32 | 143667 | 144882 |
pgsteal_normal | 31486 | 27001 |
pgsteal_movable | 0 | 0 |
pgscan_kswapd_dma | 0 | 0 |
pgscan_kswapd_dma32 | 138617 | 156351 |
pgscan_kswapd_normal | 30593 | 27955 |
pgscan_kswapd_movable | 0 | 0 |
pgscan_direct_dma | 0 | 0 |
pgscan_direct_dma32 | 5050 | 0 |
pgscan_direct_normal | 896 | 0 |
pgscan_direct_movable | 0 | 0 |
kswapd_steal | 169207 | 171883 |
kswapd_inodesteal | 0 | 0 |
kswapd_low_wmark_hit_quickly | 43 | 45 |
kswapd_high_wmark_hit_quickly | 1 | 0 |
allocstall | 32 | 0 |
As you can see, in the default case there were 32 direct reclaim (allocstall)
and its worst latency was 517.762 usecs. This value may be larger if
a process would sleep or issue I/O in the direct reclaim path. OTOH,
ii the other case where I add extra free bytes, there were no direct
reclaim and its worst latency was 20.775 usecs.
In this test case, we can avoid direct reclaim and keep a latency low.
Tested-by: Satoru Moriya <satoru.moriya@hds.com>
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next prev parent reply other threads:[~2011-09-15 3:35 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-01 14:52 [PATCH -mm] add extra free kbytes tunable Rik van Riel
2011-09-01 14:52 ` Rik van Riel
2011-09-01 17:06 ` Randy Dunlap
2011-09-01 17:06 ` Randy Dunlap
2011-09-01 19:26 ` [PATCH -v2 " Rik van Riel
2011-09-01 19:26 ` Rik van Riel
2011-09-01 21:58 ` Andrew Morton
2011-09-01 21:58 ` Andrew Morton
2011-09-01 22:08 ` David Rientjes
2011-09-01 22:08 ` David Rientjes
2011-09-01 22:16 ` Andrew Morton
2011-09-01 22:16 ` Andrew Morton
2011-09-02 16:31 ` Satoru Moriya
2011-09-02 16:31 ` Satoru Moriya
2011-10-13 7:33 ` Minchan Kim
2011-10-13 7:33 ` Minchan Kim
2011-10-13 8:09 ` KAMEZAWA Hiroyuki
2011-10-13 8:09 ` KAMEZAWA Hiroyuki
[not found] ` <E1FA588BC672D846BDBB452FCA1E308C2389B4@USINDEVS02.corp.hds.com>
2011-09-15 3:33 ` Satoru Moriya [this message]
2011-09-15 3:33 ` Satoru Moriya
2011-09-01 22:09 ` Andrew Morton
2011-09-01 22:09 ` Andrew Morton
2011-09-02 16:26 ` [PATCH -mm] fixes & cleanups for "add extra free kbytes tunable" Rik van Riel
2011-09-02 16:26 ` Rik van Riel
2011-09-30 21:43 ` [PATCH -v2 -mm] add extra free kbytes tunable Johannes Weiner
2011-09-30 21:43 ` Johannes Weiner
2011-10-08 3:08 ` David Rientjes
2011-10-08 3:08 ` David Rientjes
2011-10-10 22:37 ` Andrew Morton
2011-10-10 22:37 ` Andrew Morton
2011-10-11 19:32 ` Satoru Moriya
2011-10-11 19:32 ` Satoru Moriya
2011-10-11 19:54 ` Andrew Morton
2011-10-11 19:54 ` Andrew Morton
2011-10-11 20:23 ` Satoru Moriya
2011-10-11 20:23 ` Satoru Moriya
2011-10-11 20:54 ` Andrew Morton
2011-10-11 20:54 ` Andrew Morton
2011-10-12 13:09 ` Rik van Riel
2011-10-12 13:09 ` Rik van Riel
2011-10-12 19:20 ` Andrew Morton
2011-10-12 19:20 ` Andrew Morton
2011-10-12 19:58 ` Rik van Riel
2011-10-12 19:58 ` Rik van Riel
2011-10-12 20:26 ` David Rientjes
2011-10-12 20:26 ` David Rientjes
2011-10-21 23:48 ` Satoru Moriya
2011-10-21 23:48 ` Satoru Moriya
2011-10-23 21:22 ` David Rientjes
2011-10-23 21:22 ` David Rientjes
2011-10-25 2:04 ` Satoru Moriya
2011-10-25 2:04 ` Satoru Moriya
2011-10-25 21:50 ` David Rientjes
2011-10-25 21:50 ` David Rientjes
2011-10-26 18:59 ` Satoru Moriya
2011-10-26 18:59 ` Satoru Moriya
2011-10-12 21:08 ` Satoru Moriya
2011-10-12 21:08 ` Satoru Moriya
2011-10-12 22:41 ` David Rientjes
2011-10-12 22:41 ` David Rientjes
2011-10-12 23:52 ` Satoru Moriya
2011-10-12 23:52 ` Satoru Moriya
2011-10-13 0:01 ` David Rientjes
2011-10-13 0:01 ` David Rientjes
2011-10-13 5:35 ` KAMEZAWA Hiroyuki
2011-10-13 5:35 ` KAMEZAWA Hiroyuki
2011-10-13 20:55 ` David Rientjes
2011-10-13 20:55 ` David Rientjes
2011-10-14 22:16 ` Satoru Moriya
2011-10-14 22:16 ` Satoru Moriya
2011-10-14 22:46 ` David Rientjes
2011-10-14 22:46 ` David Rientjes
2011-10-14 5:32 ` Satoru Moriya
2011-10-14 5:32 ` Satoru Moriya
2011-10-14 5:06 ` Satoru Moriya
2011-10-14 5:06 ` Satoru Moriya
2011-10-11 23:22 ` David Rientjes
2011-10-11 23:22 ` David Rientjes
2011-10-13 16:54 ` Satoru Moriya
2011-10-13 16:54 ` Satoru Moriya
2011-10-13 20:48 ` David Rientjes
2011-10-13 20:48 ` David Rientjes
2011-10-13 21:11 ` Rik van Riel
2011-10-13 21:11 ` Rik van Riel
2011-10-13 22:02 ` David Rientjes
2011-10-13 22:02 ` David Rientjes
2011-10-11 19:20 ` Satoru Moriya
2011-10-11 19:20 ` Satoru Moriya
2011-10-11 21:04 ` David Rientjes
2011-10-11 21:04 ` David Rientjes
2011-10-12 13:13 ` Rik van Riel
2011-10-12 13:13 ` Rik van Riel
2011-10-12 20:21 ` David Rientjes
2011-10-12 20:21 ` David Rientjes
2011-10-13 4:13 ` Rik van Riel
2011-10-13 4:13 ` Rik van Riel
2011-10-13 5:22 ` David Rientjes
2011-10-13 5:22 ` David Rientjes
2011-10-22 0:11 ` Satoru Moriya
2011-10-22 0:11 ` Satoru Moriya
2011-09-09 23:01 Satoru Moriya
2011-09-09 23:01 ` Satoru Moriya
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