From: Dave Chinner <david@fromorbit.com>
To: Nick Piggin <npiggin@gmail.com>
Cc: Nick Piggin <npiggin@kernel.dk>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 00/46] rcu-walk and dcache scaling
Date: Wed, 8 Dec 2010 14:32:12 +1100 [thread overview]
Message-ID: <20101208033212.GF29333@dastard> (raw)
In-Reply-To: <AANLkTinwDr7Xga_gk4vjZ2MgGYGXhxka2JvOAVwfvKQ8@mail.gmail.com>
On Wed, Dec 08, 2010 at 12:47:42PM +1100, Nick Piggin wrote:
> On Wed, Dec 8, 2010 at 8:56 AM, Dave Chinner <david@fromorbit.com> wrote:
> > On Sat, Nov 27, 2010 at 09:15:58PM +1100, Nick Piggin wrote:
> >>
> >> git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin.git vfs-scale-working
> >>
> >> Here is an new set of vfs patches for review, not that there was much interest
> >> last time they were posted. It is structured like:
> >>
> >> * preparation patches
> >> * introduce new locks to take over dcache_lock, then remove it
> >> * cleaning up and reworking things for new locks
> >> * rcu-walk path walking
> >> * start on some fine grained locking steps
> >
> > Stress test doing:
> >
> > single thread 50M inode create
> > single thread rm -rf
> > 2-way 50M inode create
> > 2-way rm -rf
> > 4-way 50M inode create
> > 4-way rm -rf
> > 8-way 50M inode create
> > 8-way rm -rf
> > 8-way 250M inode create
> > 8-way rm -rf
> >
> > Failed about 5 minutes into the "4-way rm -rf" (~3 hours into the test)
> > with a CPU stuck spinning on here:
> >
> > [37372.084012] NMI backtrace for cpu 5
> > [37372.084012] CPU 5
> > [37372.084012] Modules linked in:
> > [37372.084012]
> > [37372.084012] Pid: 15214, comm: rm Not tainted 2.6.37-rc4-dgc+ #797 /Bochs
> > [37372.084012] RIP: 0010:[<ffffffff810643c4>] [<ffffffff810643c4>] __ticket_spin_lock+0x14/0x20
> > [37372.084012] RSP: 0018:ffff880114643c98 EFLAGS: 00000213
> > [37372.084012] RAX: 0000000000008801 RBX: ffff8800687be6c0 RCX: ffff8800c4eb2688
> > [37372.084012] RDX: ffff880114643d38 RSI: ffff8800dfd4ea80 RDI: ffff880114643d14
> > [37372.084012] RBP: ffff880114643c98 R08: 0000000000000003 R09: 0000000000000000
> > [37372.084012] R10: 0000000000000000 R11: dead000000200200 R12: ffff880114643d14
> > [37372.084012] R13: ffff880114643cb8 R14: ffff880114643d38 R15: ffff8800687be71c
> > [37372.084012] FS: 00007fd6d7c93700(0000) GS:ffff8800dfd40000(0000) knlGS:0000000000000000
> > [37372.084012] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> > [37372.084012] CR2: 0000000000bbd108 CR3: 0000000107146000 CR4: 00000000000006e0
> > [37372.084012] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > [37372.084012] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> > [37372.084012] Process rm (pid: 15214, threadinfo ffff880114642000, task ffff88011b16f890)
> > [37372.084012] Stack:
> > [37372.084012] ffff880114643ca8 ffffffff81ad044e ffff880114643cf8 ffffffff81167ae7
> > [37372.084012] 0000000000000000 ffff880114643d38 000000000000000e ffff88011901d800
> > [37372.084012] ffff8800cdb7cf5c ffff88011901d8e0 0000000000000000 0000000000000000
> > [37372.084012] Call Trace:
> > [37372.084012] [<ffffffff81ad044e>] _raw_spin_lock+0xe/0x20
> > [37372.084012] [<ffffffff81167ae7>] shrink_dentry_list+0x47/0x370
> > [37372.084012] [<ffffffff81167f5e>] __shrink_dcache_sb+0x14e/0x1e0
> > [37372.084012] [<ffffffff81168456>] shrink_dcache_parent+0x276/0x2d0
> > [37372.084012] [<ffffffff81ad044e>] ? _raw_spin_lock+0xe/0x20
> > [37372.084012] [<ffffffff8115daa2>] dentry_unhash+0x42/0x80
> > [37372.084012] [<ffffffff8115db48>] vfs_rmdir+0x68/0x100
> > [37372.084012] [<ffffffff8115fd93>] do_rmdir+0x113/0x130
> > [37372.084012] [<ffffffff8114f5ad>] ? filp_close+0x5d/0x90
> > [37372.084012] [<ffffffff8115fde5>] sys_unlinkat+0x35/0x40
> > [37372.084012] [<ffffffff8103a002>] system_call_fastpath+0x16/0x1b
>
> OK good, with any luck, that's the same bug.
>
> Is this XFS?
Yes.
> Is there any concurrent activity happening on the same dentries?
Not from an application perspective.
> Ie. are the rm -rf threads running on the same directories,
No, each thread operating on a different directory.
> or is there any reclaim happening in the background?
IIRC, kswapd was consuming about 5-10% of a CPU during parallel
unlink tests. Mainly reclaiming XFS inodes, I think, but there may
be dentry cache reclaim going as well.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2010-12-08 3:32 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-27 10:15 [PATCH 00/46] rcu-walk and dcache scaling Nick Piggin
2010-11-27 9:44 ` [PATCH 02/46] fs: d_validate fixes Nick Piggin
2010-12-08 1:53 ` Dave Chinner
2010-12-08 6:59 ` Nick Piggin
2010-12-09 0:50 ` Dave Chinner
2010-12-09 4:50 ` Nick Piggin
2010-11-27 9:44 ` [PATCH 03/46] kernel: kmem_ptr_validate considered harmful Nick Piggin
2010-11-27 9:44 ` [PATCH 04/46] fs: dcache documentation cleanup Nick Piggin
2010-11-27 9:44 ` [PATCH 05/46] fs: change d_delete semantics Nick Piggin
2010-11-27 9:44 ` [PATCH 06/46] cifs: dont overwrite dentry name in d_revalidate Nick Piggin
2010-11-27 9:44 ` [PATCH 07/46] jfs: " Nick Piggin
2010-11-27 9:44 ` [PATCH 08/46] fs: change d_compare for rcu-walk Nick Piggin
2010-11-27 9:44 ` [PATCH 09/46] fs: change d_hash " Nick Piggin
2010-11-27 9:44 ` [PATCH 10/46] hostfs: simplify locking Nick Piggin
2010-11-27 9:44 ` [PATCH 11/46] fs: dcache scale hash Nick Piggin
2010-12-09 6:09 ` Dave Chinner
2010-12-09 6:28 ` Nick Piggin
2010-12-09 8:17 ` Dave Chinner
2010-12-09 12:53 ` Nick Piggin
2010-12-09 23:42 ` Dave Chinner
2010-12-10 2:35 ` Nick Piggin
2010-12-10 9:01 ` Dave Chinner
2010-12-13 4:48 ` Nick Piggin
2010-12-13 5:05 ` Nick Piggin
2010-11-27 9:44 ` [PATCH 12/46] fs: dcache scale lru Nick Piggin
2010-12-09 7:22 ` Dave Chinner
2010-12-09 12:34 ` Nick Piggin
2010-11-27 9:44 ` [PATCH 13/46] fs: dcache scale dentry refcount Nick Piggin
2010-11-27 9:44 ` [PATCH 14/46] fs: dcache scale d_unhashed Nick Piggin
2010-11-27 9:44 ` [PATCH 15/46] fs: dcache scale subdirs Nick Piggin
2010-11-27 9:44 ` [PATCH 16/46] fs: scale inode alias list Nick Piggin
2010-11-27 9:44 ` [PATCH 17/46] fs: Use rename lock and RCU for multi-step operations Nick Piggin
2011-01-18 22:32 ` Yehuda Sadeh Weinraub
2011-01-18 22:42 ` Nick Piggin
2011-01-19 22:27 ` Yehuda Sadeh Weinraub
2011-01-19 22:32 ` Nick Piggin
2011-01-25 22:10 ` Yehuda Sadeh Weinraub
2011-01-27 5:18 ` Nick Piggin
2011-02-07 18:52 ` Jim Schutt
2011-02-07 21:04 ` Yehuda Sadeh Weinraub
2011-02-07 21:31 ` Jim Schutt
2011-02-07 22:25 ` Jim Schutt
2011-02-14 17:57 ` Yehuda Sadeh Weinraub
2010-11-27 9:44 ` [PATCH 18/46] fs: increase d_name lock coverage Nick Piggin
2010-11-27 9:44 ` [PATCH 19/46] fs: dcache remove dcache_lock Nick Piggin
2010-11-27 9:44 ` [PATCH 20/46] fs: dcache avoid starvation in dcache multi-step operations Nick Piggin
2010-11-27 9:44 ` [PATCH 21/46] fs: dcache reduce dput locking Nick Piggin
2010-11-27 9:44 ` [PATCH 22/46] fs: dcache reduce locking in d_alloc Nick Piggin
2010-11-27 9:44 ` [PATCH 23/46] fs: dcache reduce dcache_inode_lock Nick Piggin
2010-11-27 9:44 ` [PATCH 24/46] fs: dcache rationalise dget variants Nick Piggin
2010-11-27 9:44 ` [PATCH 25/46] fs: dcache reduce d_parent locking Nick Piggin
2010-11-27 9:44 ` [PATCH 26/46] fs: dcache reduce prune_one_dentry locking Nick Piggin
2010-11-27 9:44 ` [PATCH 27/46] fs: reduce dcache_inode_lock width in lru scanning Nick Piggin
2010-11-27 9:44 ` [PATCH 28/46] fs: use RCU in shrink_dentry_list to reduce lock nesting Nick Piggin
2010-11-27 9:44 ` [PATCH 29/46] fs: consolidate dentry kill sequence Nick Piggin
2010-11-27 9:45 ` [PATCH 30/46] fs: icache RCU free inodes Nick Piggin
2010-11-27 9:45 ` [PATCH 31/46] fs: avoid inode RCU freeing for pseudo fs Nick Piggin
2010-11-27 9:45 ` [PATCH 32/46] kernel: optimise seqlock Nick Piggin
2010-11-27 9:45 ` [PATCH 33/46] fs: rcu-walk for path lookup Nick Piggin
2010-11-27 9:45 ` [PATCH 34/46] fs: fs_struct use seqlock Nick Piggin
2010-11-27 9:45 ` [PATCH 35/46] fs: dcache remove d_mounted Nick Piggin
2010-11-27 9:45 ` [PATCH 36/46] fs: dcache reduce branches in lookup path Nick Piggin
2010-11-27 9:45 ` [PATCH 37/46] fs: cache optimise dentry and inode for rcu-walk Nick Piggin
2010-11-27 9:45 ` [PATCH 38/46] fs: prefetch inode data in dcache lookup Nick Piggin
2010-11-27 9:45 ` [PATCH 39/46] fs: d_revalidate_rcu for rcu-walk Nick Piggin
2010-11-27 9:45 ` [PATCH 40/46] fs: provide rcu-walk aware permission i_ops Nick Piggin
2010-11-27 9:45 ` [PATCH 41/46] fs: provide simple rcu-walk ACL implementation Nick Piggin
2010-11-27 9:45 ` [PATCH 42/46] kernel: add bl_list Nick Piggin
2010-11-27 9:45 ` [PATCH 43/46] bit_spinlock: add required includes Nick Piggin
2010-11-27 9:45 ` [PATCH 44/46] fs: dcache per-bucket dcache hash locking Nick Piggin
2010-11-27 9:45 ` [PATCH 45/46] fs: dcache per-inode inode alias locking Nick Piggin
2010-11-27 9:45 ` [PATCH 46/46] fs: improve scalability of pseudo filesystems Nick Piggin
2010-11-27 9:56 ` [PATCH 01/46] Revert "fs: use RCU read side protection in d_validate" Nick Piggin
2010-12-08 1:16 ` Dave Chinner
2010-12-08 9:38 ` Nick Piggin
2010-12-09 0:44 ` Dave Chinner
2010-12-09 4:38 ` Nick Piggin
2010-12-09 5:16 ` Nick Piggin
2010-11-27 15:04 ` [PATCH 00/46] rcu-walk and dcache scaling Anca Emanuel
2010-11-28 3:28 ` Nick Piggin
2010-11-28 6:24 ` Sedat Dilek
2010-12-01 18:03 ` David Miller
2010-12-03 16:55 ` Nick Piggin
2010-12-07 11:25 ` Dave Chinner
2010-12-07 15:24 ` Nick Piggin
2010-12-07 15:49 ` Peter Zijlstra
2010-12-07 15:59 ` Nick Piggin
2010-12-07 16:23 ` Peter Zijlstra
2010-12-08 3:28 ` Nick Piggin
2010-12-07 21:56 ` Dave Chinner
2010-12-08 1:47 ` Nick Piggin
2010-12-08 3:32 ` Dave Chinner [this message]
2010-12-08 4:28 ` Dave Chinner
2010-12-08 7:09 ` Nick Piggin
2010-12-10 20:32 ` Paul E. McKenney
2010-12-12 14:54 ` Paul E. McKenney
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