From: Lin Ming <ming.m.lin@intel.com>
To: "Wu, Fengguang" <fengguang.wu@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
"npiggin@suse.de" <npiggin@suse.de>,
linux-kernel <linux-kernel@vger.kernel.org>,
"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Subject: Re: iozone regression with 2.6.29-rc6
Date: Mon, 02 Mar 2009 11:16:41 +0800 [thread overview]
Message-ID: <1235963801.11610.251.camel@minggr> (raw)
In-Reply-To: <20090302031227.GA6686@localhost>
On Mon, 2009-03-02 at 11:12 +0800, Wu, Fengguang wrote:
> On Mon, Mar 02, 2009 at 10:19:04AM +0800, Lin, Ming wrote:
> > On Fri, 2009-02-27 at 17:49 +0800, Peter Zijlstra wrote:
> > > On Fri, 2009-02-27 at 17:13 +0800, Lin Ming wrote:
> > > > bisect locates below commits,
> > > >
> > > > commit 1cf6e7d83bf334cc5916137862c920a97aabc018
> > > > Author: Nick Piggin <npiggin@suse.de>
> > > > Date: Wed Feb 18 14:48:18 2009 -0800
> > > >
> > > > mm: task dirty accounting fix
> > > >
> > > > YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for
> > > > cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty).
> > > >
> > > > Additionally, there is some inconsistency about when task_dirty_inc is
> > > > called. It is used for dirty balancing, however it even gets called for
> > > > __set_page_dirty_no_writeback.
> > > >
> > > > So rather than increment it in a set_page_dirty wrapper, move it down to
> > > > exactly where the dirty page accounting stats are incremented.
> > > >
> > > > Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
> > > > Signed-off-by: Nick Piggin <npiggin@suse.de>
> > > > Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> > > > Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> > > > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> > > >
> > > >
> > > > below data in parenthesis is the result after above commit reverted, for example,
> > > > -10% (+2%) means,
> > > > iozone has ~10% regression with 2.6.29-rc6 compared with 2.6.29-rc5.
> > > > and
> > > > iozone has ~2% improvement with 2.6.29-rc6-revert-1cf6e7d compared with 2.6.29-rc5.
> > > >
> > > >
> > > > 4P dual-core HT 2P qual-core 2P qual-core HT
> > > > tulsa stockley Nehalem
> > > > --------------------------------------------------------
> > > > iozone-rewrite -10% (+2%) -8% (0%) -10% (-7%)
> > > > iozone-rand-write -50% (0%) -20% (+10%)
> > > > iozone-read -13% (0%)
> > > > iozone-write -28% (-1%)
> > > > iozone-reread -5% (-1%)
> > > > iozone-mmap-read -7% (+2%)
> > > > iozone-mmap-reread -7% (+2%)
> > > > iozone-mmap-rand-read -7% (+3%)
> > > > iozone-mmap-rand-write -5% (0%)
> > >
> > > Ugh, that's unexpected..
> > >
> > > So 'better' accounting leads to worse performance, which would indicate
> > > we throttle more.
> > >
> > > I take it you machine has gobs of memory.
> > >
> > > Does something like the below help any?
> >
> > It helps some as below test result,
> > The data in second parenthesis means 2.6.29-rc6-with-peter's-patch
> > compared with 2.6.29-rc5.
> >
> > 4P dual-core HT 2P qual-core 2P qual-core HT
> > tulsa stockley Nehalem
> > --------------------------------------------------------
> > iozone-rewrite -10% (+2%)(-3%) -8% (0%)(0%) -10% (-7%)(-2%)
> > iozone-rand-write -50% (0%)(-10%) -20% (+10%)(+3%)
> > iozone-read -13% (0%)(-8%)
> > iozone-write -28% (-1%)(+35%)
> > iozone-reread -5% (-1%)(-1%)
> > iozone-mmap-read -7% (+2%)(-7%)
> > iozone-mmap-reread -7% (+2%)(-7%)
> > iozone-mmap-rand-read -7% (+3%)(-7%)
> > iozone-mmap-rand-write -5% (0%)(+27%)
>
> Thanks, Lin Ming. To better understand the situation, would you please
> provide the iozone command and memory info about the servers?
iozone -i 0 -i 1 -i 2 -i 3 -i 4 -r 4k -s 64k -s 512m -s 1200m -b tmp.xls
iozone -B -r 4k -s 64k -s 512m -s 1200m -b tmp.xls
4P dual-core HT tulsa /proc/meminfo
------------------------------------
MemTotal: 8189476 kB
MemFree: 7915884 kB
Buffers: 32676 kB
Cached: 139784 kB
SwapCached: 0 kB
Active: 35852 kB
Inactive: 145564 kB
Active(anon): 9048 kB
Inactive(anon): 0 kB
Active(file): 26804 kB
Inactive(file): 145564 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 140 kB
Writeback: 0 kB
AnonPages: 9068 kB
Mapped: 4084 kB
Slab: 31180 kB
SReclaimable: 14800 kB
SUnreclaim: 16380 kB
PageTables: 1236 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 4094736 kB
Committed_AS: 18446744073709545248 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 286416 kB
VmallocChunk: 34359449467 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 4096 kB
DirectMap2M: 8380416
2P qual-core stockley /proc/meminfo
-----------------------------------
MemTotal: 8167260 kB
MemFree: 7951068 kB
Buffers: 30988 kB
Cached: 123772 kB
SwapCached: 0 kB
Active: 34744 kB
Inactive: 129296 kB
Active(anon): 9412 kB
Inactive(anon): 0 kB
Active(file): 25332 kB
Inactive(file): 129296 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 272 kB
Writeback: 0 kB
AnonPages: 9408 kB
Mapped: 4072 kB
Slab: 21760 kB
SReclaimable: 10612 kB
SUnreclaim: 11148 kB
PageTables: 1260 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 4083628 kB
Committed_AS: 18446744073709540996 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 11216 kB
VmallocChunk: 34359726459 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 7168 kB
DirectMap2M: 8380416 kB
2P qual-core HT Nehalem /proc/meminfo
-------------------------------------
MemTotal: 6113044 kB
MemFree: 5947476 kB
Buffers: 17056 kB
Cached: 44280 kB
SwapCached: 0 kB
Active: 31268 kB
Inactive: 40300 kB
Active(anon): 10308 kB
Inactive(anon): 0 kB
Active(file): 20960 kB
Inactive(file): 40300 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 280 kB
Writeback: 0 kB
AnonPages: 10328 kB
Mapped: 5096 kB
Slab: 27844 kB
SReclaimable: 10988 kB
SUnreclaim: 16856 kB
PageTables: 2204 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 3056520 kB
Committed_AS: 18446744073709542732 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 286428 kB
VmallocChunk: 34359451259 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 8192 kB
DirectMap2M: 6275072 kB
Lin Ming
>
> Thanks,
> Fengguang
prev parent reply other threads:[~2009-03-02 3:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-27 9:13 iozone regression with 2.6.29-rc6 Lin Ming
2009-02-27 9:49 ` Peter Zijlstra
2009-02-27 11:55 ` Nick Piggin
2009-03-02 2:19 ` Lin Ming
2009-03-02 3:12 ` Wu Fengguang
2009-03-02 3:16 ` Lin Ming [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1235963801.11610.251.camel@minggr \
--to=ming.m.lin@intel.com \
--cc=a.p.zijlstra@chello.nl \
--cc=fengguang.wu@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=npiggin@suse.de \
--cc=yanmin_zhang@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.