From: Nick Piggin <npiggin@kernel.dk>
To: Dave Chinner <david@fromorbit.com>
Cc: Nick Piggin <npiggin@kernel.dk>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Frank Mayhar <fmayhar@google.com>,
John Stultz <johnstul@us.ibm.com>
Subject: Re: VFS scalability git tree
Date: Sat, 24 Jul 2010 02:16:13 +1000 [thread overview]
Message-ID: <20100723161613.GB6316@amd> (raw)
In-Reply-To: <20100723135514.GJ32635@dastard>
On Fri, Jul 23, 2010 at 11:55:14PM +1000, Dave Chinner wrote:
> On Fri, Jul 23, 2010 at 05:01:00AM +1000, Nick Piggin wrote:
> > I'm pleased to announce I have a git tree up of my vfs scalability work.
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin.git
> > http://git.kernel.org/?p=linux/kernel/git/npiggin/linux-npiggin.git
> >
> > Branch vfs-scale-working
>
> Bug's I've noticed so far:
>
> - Using XFS, the existing vfs inode count statistic does not decrease
> as inodes are free.
> - the existing vfs dentry count remains at zero
> - the existing vfs free inode count remains at zero
>
> $ pminfo -f vfs.inodes vfs.dentry
>
> vfs.inodes.count
> value 7472612
>
> vfs.inodes.free
> value 0
>
> vfs.dentry.count
> value 0
>
> vfs.dentry.free
> value 0
Hm, I must have broken it along the way and not noticed. Thanks
for pointing that out.
> With a production build (i.e. no lockdep, no xfs debug), I'll
> run the same fs_mark parallel create/unlink workload to show
> scalability as I ran here:
>
> http://oss.sgi.com/archives/xfs/2010-05/msg00329.html
>
> The numbers can't be directly compared, but the test and the setup
> is the same. The XFS numbers below are with delayed logging
> enabled. ext4 is using default mkfs and mount parameters except for
> barrier=0. All numbers are averages of three runs.
>
> fs_mark rate (thousands of files/second)
> 2.6.35-rc5 2.6.35-rc5-scale
> threads xfs ext4 xfs ext4
> 1 20 39 20 39
> 2 35 55 35 57
> 4 60 41 57 42
> 8 79 9 75 9
>
> ext4 is getting IO bound at more than 2 threads, so apart from
> pointing out that XFS is 8-9x faster than ext4 at 8 thread, I'm
> going to ignore ext4 for the purposes of testing scalability here.
>
> For XFS w/ delayed logging, 2.6.35-rc5 is only getting to about 600%
> CPU and with Nick's patches it's about 650% (10% higher) for
> slightly lower throughput. So at this class of machine for this
> workload, the changes result in a slight reduction in scalability.
That's a good test case, thanks. I'll see if I can find where
this is coming from. I will suspect RCU-inodes I suppose. Hm,
may have to make them DESTROY_BY_RCU afterall.
Thanks,
Nick
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next prev parent reply other threads:[~2010-07-23 16:16 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-22 19:01 VFS scalability git tree Nick Piggin
2010-07-23 11:13 ` Dave Chinner
2010-07-23 14:04 ` [PATCH 0/2] vfs scalability tree fixes Dave Chinner
2010-07-23 16:09 ` Nick Piggin
2010-07-23 14:04 ` [PATCH 1/2] xfs: fix shrinker build Dave Chinner
2010-07-23 14:04 ` [PATCH 2/2] xfs: shrinker should use a per-filesystem scan count Dave Chinner
2010-07-23 15:51 ` VFS scalability git tree Nick Piggin
2010-07-24 0:21 ` Dave Chinner
2010-07-23 11:17 ` Christoph Hellwig
2010-07-23 15:42 ` Nick Piggin
2010-07-23 13:55 ` Dave Chinner
2010-07-23 16:16 ` Nick Piggin [this message]
2010-07-27 7:05 ` Nick Piggin
2010-07-27 11:09 ` Nick Piggin
2010-07-27 13:18 ` Dave Chinner
2010-07-27 15:09 ` Nick Piggin
2010-07-28 4:59 ` Dave Chinner
2010-07-23 15:35 ` Nick Piggin
2010-07-24 8:43 ` KOSAKI Motohiro
2010-07-24 8:44 ` [PATCH 1/2] vmscan: shrink_all_slab() use reclaim_state instead the return value of shrink_slab() KOSAKI Motohiro
2010-07-24 12:05 ` KOSAKI Motohiro
2010-07-24 8:46 ` [PATCH 2/2] vmscan: change shrink_slab() return tyep with void KOSAKI Motohiro
2010-07-24 10:54 ` VFS scalability git tree KOSAKI Motohiro
2010-07-26 5:41 ` Nick Piggin
2010-07-28 10:24 ` Nick Piggin
2010-07-30 9:12 ` Nick Piggin
2010-08-03 0:27 ` john stultz
2010-08-03 5:44 ` Nick Piggin
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