From: Nick Piggin <npiggin@suse.de>
To: Dave Chinner <david@fromorbit.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
John Stultz <johnstul@us.ibm.com>,
Frank Mayhar <fmayhar@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [patch 00/52] vfs scalability patches updated
Date: Wed, 7 Jul 2010 03:49:36 +1000 [thread overview]
Message-ID: <20100706174935.GK11732@laptop> (raw)
In-Reply-To: <20100701172317.GB1830@laptop>
On Fri, Jul 02, 2010 at 03:23:17AM +1000, Nick Piggin wrote:
> On Wed, Jun 30, 2010 at 10:40:49PM +1000, Nick Piggin wrote:
> > But actually it's not all for scalability. I have some follow on patches
> > (that require RCU inodes, among other things) that actually improve
> > single threaded performance significnatly. git diff workload IIRC was
> > several % improved from speeding up stat(2).
>
> I rewrote the store-free path walk patch that goes on top of this
> patchset (it's now much cleaner and more optimised, I'll post a patch
> soonish). It is quicker than I remembered.
>
> A single thread running stat(2) in a loop on a file "./file" has the
> following cost (on an 2s8c Barcelona):
>
> 2.6.35-rc3 595 ns/op
> patched 336 ns/op
>
> stat(2) takes 56% the time with patches. It's something like 13 fewer
> atomic operations per syscall.
>
> What's that good for? A single threaded, cached `git diff` on the linux
> kernel tree takes just 81% of the time after the vfs patches (0.27s vs
> 0.33s).
At the other end of the scale, I tried dbench on ramfs on the little
32n64c Altix. Dbench actually has statfs() call completely removed from
the workload -- it's still a little problematic and patched kernel
throughput is ~halved with statfs().
dbench procs 1 64
2.6.35-rc3 235MB/s 95MB/s ( 0.6% scaling)
patched 245MB/s 14870MB/s (94.8% scaling)
(note all these numbers are with store-free path walking patches on top
of the posted patchset -- dbench procs do path walking from common cwds
so it will never scale this well if we have to take refcounts on common
dentries)
Thanks,
Nick
next prev parent reply other threads:[~2010-07-06 17:49 UTC|newest]
Thread overview: 152+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-24 3:02 [patch 00/52] vfs scalability patches updated npiggin
2010-06-24 3:02 ` [patch 01/52] kernel: add bl_list npiggin
2010-06-24 6:04 ` Eric Dumazet
2010-06-24 14:42 ` Nick Piggin
2010-06-24 16:01 ` Eric Dumazet
2010-06-28 21:37 ` Paul E. McKenney
2010-06-29 6:30 ` Nick Piggin
2010-06-24 3:02 ` [patch 02/52] fs: fix superblock iteration race npiggin
2010-06-29 13:02 ` Christoph Hellwig
2010-06-29 14:56 ` Nick Piggin
2010-06-29 17:35 ` Linus Torvalds
2010-06-29 17:41 ` Nick Piggin
2010-06-29 17:52 ` Linus Torvalds
2010-06-29 17:58 ` Linus Torvalds
2010-06-29 20:04 ` Chris Clayton
2010-06-29 20:14 ` Nick Piggin
2010-06-29 20:38 ` Chris Clayton
2010-06-30 7:13 ` Chris Clayton
2010-06-30 12:51 ` Al Viro
2010-06-24 3:02 ` [patch 03/52] fs: fs_struct rwlock to spinlock npiggin
2010-06-24 3:02 ` [patch 04/52] fs: cleanup files_lock npiggin
2010-06-24 3:02 ` [patch 05/52] lglock: introduce special lglock and brlock spin locks npiggin
2010-06-24 18:15 ` Thomas Gleixner
2010-06-25 6:22 ` Nick Piggin
2010-06-25 9:50 ` Thomas Gleixner
2010-06-25 10:11 ` Nick Piggin
2010-06-24 3:02 ` [patch 06/52] fs: scale files_lock npiggin
2010-06-24 7:52 ` Peter Zijlstra
2010-06-24 15:00 ` Nick Piggin
2010-06-24 3:02 ` [patch 07/52] fs: brlock vfsmount_lock npiggin
2010-06-24 3:02 ` [patch 08/52] fs: scale mntget/mntput npiggin
2010-06-24 3:02 ` [patch 09/52] fs: dcache scale hash npiggin
2010-06-24 3:02 ` [patch 10/52] fs: dcache scale lru npiggin
2010-06-24 3:02 ` [patch 11/52] fs: dcache scale nr_dentry npiggin
2010-06-24 3:02 ` [patch 12/52] fs: dcache scale dentry refcount npiggin
2010-06-24 3:02 ` [patch 13/52] fs: dcache scale d_unhashed npiggin
2010-06-24 3:02 ` [patch 14/52] fs: dcache scale subdirs npiggin
2010-06-24 7:56 ` Peter Zijlstra
2010-06-24 9:50 ` Andi Kleen
2010-06-24 15:53 ` Nick Piggin
2010-06-24 3:02 ` [patch 15/52] fs: dcache scale inode alias list npiggin
2010-06-24 3:02 ` [patch 16/52] fs: dcache RCU for multi-step operaitons npiggin
2010-06-24 7:58 ` Peter Zijlstra
2010-06-24 15:03 ` Nick Piggin
2010-06-24 17:22 ` john stultz
2010-06-24 17:26 ` john stultz
2010-06-25 6:45 ` Nick Piggin
2010-06-24 3:02 ` [patch 17/52] fs: dcache remove dcache_lock npiggin
2010-06-24 3:02 ` [patch 18/52] fs: dcache reduce dput locking npiggin
2010-06-24 3:02 ` [patch 19/52] fs: dcache per-bucket dcache hash locking npiggin
2010-06-24 3:02 ` [patch 20/52] fs: dcache reduce dcache_inode_lock npiggin
2010-06-24 3:02 ` [patch 21/52] fs: dcache per-inode inode alias locking npiggin
2010-06-24 3:02 ` [patch 22/52] fs: dcache rationalise dget variants npiggin
2010-06-24 3:02 ` [patch 23/52] fs: dcache percpu nr_dentry npiggin
2010-06-24 3:02 ` [patch 24/52] fs: dcache reduce d_parent locking npiggin
2010-06-24 8:44 ` Peter Zijlstra
2010-06-24 15:07 ` Nick Piggin
2010-06-24 15:32 ` Paul E. McKenney
2010-06-24 16:05 ` Nick Piggin
2010-06-24 16:41 ` Paul E. McKenney
2010-06-28 21:50 ` Paul E. McKenney
2010-07-07 14:35 ` Nick Piggin
2010-06-24 3:02 ` [patch 25/52] fs: dcache DCACHE_REFERENCED improve npiggin
2010-06-24 3:02 ` [patch 26/52] fs: icache lock s_inodes list npiggin
2010-06-24 3:02 ` [patch 27/52] fs: icache lock inode hash npiggin
2010-06-24 3:02 ` [patch 28/52] fs: icache lock i_state npiggin
2010-06-24 3:02 ` [patch 29/52] fs: icache lock i_count npiggin
2010-06-30 7:27 ` Dave Chinner
2010-06-30 12:05 ` Nick Piggin
2010-07-01 2:36 ` Dave Chinner
2010-07-01 7:54 ` Nick Piggin
2010-07-01 9:36 ` Nick Piggin
2010-07-01 16:21 ` Frank Mayhar
2010-07-03 2:03 ` Andrew Morton
2010-07-03 3:41 ` Nick Piggin
2010-07-03 4:31 ` Andrew Morton
2010-07-03 5:06 ` Nick Piggin
2010-07-03 5:18 ` Nick Piggin
2010-07-05 22:41 ` Dave Chinner
2010-07-06 4:34 ` Nick Piggin
2010-07-06 10:38 ` Theodore Tso
2010-07-06 13:04 ` Nick Piggin
2010-07-07 17:00 ` Frank Mayhar
2010-06-24 3:02 ` [patch 30/52] fs: icache lock lru/writeback lists npiggin
2010-06-24 8:58 ` Peter Zijlstra
2010-06-24 15:09 ` Nick Piggin
2010-06-24 15:13 ` Peter Zijlstra
2010-06-24 3:02 ` [patch 31/52] fs: icache atomic inodes_stat npiggin
2010-06-24 3:02 ` [patch 32/52] fs: icache protect inode state npiggin
2010-06-24 3:02 ` [patch 33/52] fs: icache atomic last_ino, iunique lock npiggin
2010-06-24 3:02 ` [patch 34/52] fs: icache remove inode_lock npiggin
2010-06-24 3:02 ` [patch 35/52] fs: icache factor hash lock into functions npiggin
2010-06-24 3:02 ` [patch 36/52] fs: icache per-bucket inode hash locks npiggin
2010-06-24 3:02 ` [patch 37/52] fs: icache lazy lru npiggin
2010-06-24 9:52 ` Andi Kleen
2010-06-24 15:59 ` Nick Piggin
2010-06-30 8:38 ` Dave Chinner
2010-06-30 12:06 ` Nick Piggin
2010-07-01 2:46 ` Dave Chinner
2010-07-01 7:57 ` Nick Piggin
2010-06-24 3:02 ` [patch 38/52] fs: icache RCU free inodes npiggin
2010-06-30 8:57 ` Dave Chinner
2010-06-30 12:07 ` Nick Piggin
2010-06-24 3:02 ` [patch 39/52] fs: icache rcu walk for i_sb_list npiggin
2010-06-24 3:02 ` [patch 40/52] fs: dcache improve scalability of pseudo filesystems npiggin
2010-06-24 3:02 ` [patch 41/52] fs: icache reduce atomics npiggin
2010-06-24 3:02 ` [patch 42/52] fs: icache per-cpu last_ino allocator npiggin
2010-06-24 9:48 ` Andi Kleen
2010-06-24 15:52 ` Nick Piggin
2010-06-24 16:19 ` Andi Kleen
2010-06-24 16:38 ` Nick Piggin
2010-06-24 3:02 ` [patch 43/52] fs: icache per-cpu nr_inodes counter npiggin
2010-06-24 3:02 ` [patch 44/52] fs: icache per-CPU sb inode lists and locks npiggin
2010-06-30 9:26 ` Dave Chinner
2010-06-30 12:08 ` Nick Piggin
2010-07-01 3:12 ` Dave Chinner
2010-07-01 8:00 ` Nick Piggin
2010-06-24 3:02 ` [patch 45/52] fs: icache RCU hash lookups npiggin
2010-06-24 3:02 ` [patch 46/52] fs: icache reduce locking npiggin
2010-06-24 3:02 ` [patch 47/52] fs: keep inode with backing-dev npiggin
2010-06-24 3:03 ` [patch 48/52] fs: icache split IO and LRU lists npiggin
2010-06-24 3:03 ` [patch 49/52] fs: icache scale writeback list locking npiggin
2010-06-24 3:03 ` [patch 50/52] mm: implement per-zone shrinker npiggin
2010-06-24 10:06 ` Andi Kleen
2010-06-24 16:00 ` Nick Piggin
2010-06-24 16:27 ` Andi Kleen
2010-06-24 16:32 ` Andi Kleen
2010-06-24 16:37 ` Andi Kleen
2010-06-30 6:28 ` Dave Chinner
2010-06-30 12:03 ` Nick Piggin
2010-06-24 3:03 ` [patch 51/52] fs: per-zone dentry and inode LRU npiggin
2010-06-30 10:09 ` Dave Chinner
2010-06-30 12:13 ` Nick Piggin
2010-06-24 3:03 ` [patch 52/52] fs: icache less I_FREEING time npiggin
2010-06-30 10:13 ` Dave Chinner
2010-06-30 12:14 ` Nick Piggin
2010-07-01 3:33 ` Dave Chinner
2010-07-01 8:06 ` Nick Piggin
2010-06-25 7:12 ` [patch 00/52] vfs scalability patches updated Christoph Hellwig
2010-06-25 8:05 ` Nick Piggin
2010-06-30 11:30 ` Dave Chinner
2010-06-30 12:40 ` Nick Piggin
2010-07-01 3:56 ` Dave Chinner
2010-07-01 8:20 ` Nick Piggin
2010-07-01 17:36 ` Andi Kleen
2010-07-01 17:23 ` Nick Piggin
2010-07-01 17:28 ` Andi Kleen
2010-07-06 17:49 ` Nick Piggin [this message]
2010-07-01 17:35 ` Linus Torvalds
2010-07-01 17:52 ` Nick Piggin
2010-07-02 4:01 ` Paul E. McKenney
2010-06-30 17:08 ` Frank Mayhar
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