From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Nick Piggin <npiggin@gmail.com>
Cc: Dave Chinner <david@fromorbit.com>,
Nick Piggin <npiggin@kernel.dk>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
MingLei <tom.leiming@gmail.com>
Subject: Re: [PATCH 00/46] rcu-walk and dcache scaling
Date: Tue, 07 Dec 2010 17:23:02 +0100 [thread overview]
Message-ID: <1291738982.2032.720.camel@laptop> (raw)
In-Reply-To: <AANLkTim=aqwYsyR9fb=DTj2BNA5BmwsXRAPz-+OvUZPV@mail.gmail.com>
On Wed, 2010-12-08 at 02:59 +1100, Nick Piggin wrote:
> OK, thanks. My version should not have caused any problems though,
> right?
I tihnk so, yes, altough looking at it again I wonder why you use
spin_aquire(.trylock=1) -- but that too shouldn't cause anything like
the explosion.
> Any idea what might have caused Dave's crash?
Not directly, no. Usually lockdep crashes indicate use after free like
things, where we try to lock a lock that's been scribbled on. But that
usually explodes a bit earlier.
You faulting in the middle of that breath-first-search does suggest some
data corruption, but I'm not quite sure what kind, I can't remember ever
having seem something like this before.
I've CC'ed Ming Lei who wrote the bfs search, maybe he's got an idea.
Copy of the splat:
---
> [ 5954.061633] BUG: sleeping function called from invalid context at arch/x86/mm/fault.c:1081
> [ 5954.062466] in_atomic(): 0, irqs_disabled(): 1, pid: 2927, name: rm
> [ 5954.063122] 3 locks held by rm/2927:
> [ 5954.063476] #0: (&sb->s_type->i_mutex_key#12/1){+.+.+.}, at: [<ffffffff8116f5e1>] do_rmdir+0x81/0x130
> [ 5954.064014] #1: (&sb->s_type->i_mutex_key#12){+.+.+.}, at: [<ffffffff8116d3a8>] vfs_rmdir+0x58/0xe0
> [ 5954.064014] #2: (rcu_read_lock){.+.+..}, at: [<ffffffff811779c0>] shrink_dentry_list+0x0/0x430
> [ 5954.064014] irq event stamp: 1484376719
> [ 5954.064014] hardirqs last enabled at (1484376719): [<ffffffff810ebf07>] __call_rcu+0xd7/0x1a0
> [ 5954.064014] hardirqs last disabled at (1484376718): [<ffffffff810ebe7a>] __call_rcu+0x4a/0x1a0
> [ 5954.064014] softirqs last enabled at (1484376586): [<ffffffff8108b911>] __do_softirq+0x161/0x270
> [ 5954.064014] softirqs last disabled at (1484376581): [<ffffffff8103af1c>] call_softirq+0x1c/0x50
> [ 5954.064014] Pid: 2927, comm: rm Not tainted 2.6.37-rc4-dgc+ #794
> [ 5954.064014] Call Trace:
> [ 5954.064014] [<ffffffff810b95b0>] ? print_irqtrace_events+0xd0/0xe0
> [ 5954.064014] [<ffffffff81076455>] __might_sleep+0xf5/0x130
> [ 5954.064014] [<ffffffff81b1e603>] do_page_fault+0x103/0x4f0
> [ 5954.064014] [<ffffffff810645b8>] ? pvclock_clocksource_read+0x58/0xd0
> [ 5954.064014] [<ffffffff810645b8>] ? pvclock_clocksource_read+0x58/0xd0
> [ 5954.064014] [<ffffffff810645b8>] ? pvclock_clocksource_read+0x58/0xd0
> [ 5954.064014] [<ffffffff81b19b28>] ? trace_hardirqs_off_thunk+0x3a/0x3c
> [ 5954.064014] [<ffffffff810b8e20>] ? usage_match+0x0/0x20
> [ 5954.064014] [<ffffffff81b1af25>] page_fault+0x25/0x30
> [ 5954.064014] [<ffffffff810b8e20>] ? usage_match+0x0/0x20
> [ 5954.064014] [<ffffffff810ba1c8>] ? __bfs+0xc8/0x260
> [ 5954.064014] [<ffffffff810ba123>] ? __bfs+0x23/0x260
> [ 5954.064014] [<ffffffff810ba4d2>] find_usage_backwards+0x42/0x80
> [ 5954.064014] [<ffffffff810bcec4>] check_usage_backwards+0x64/0xf0
> [ 5954.064014] [<ffffffff8104796f>] ? save_stack_trace+0x2f/0x50
> [ 5954.064014] [<ffffffff810bce60>] ? check_usage_backwards+0x0/0xf0
> [ 5954.064014] [<ffffffff810bd9a9>] mark_lock+0x1a9/0x440
> [ 5954.064014] [<ffffffff810be989>] __lock_acquire+0x5a9/0x14b0
> [ 5954.064014] [<ffffffff810be716>] ? __lock_acquire+0x336/0x14b0
> [ 5954.064014] [<ffffffff810645b8>] ? pvclock_clocksource_read+0x58/0xd0
> [ 5954.064014] [<ffffffff810bf944>] lock_acquire+0xb4/0x140
> [ 5954.064014] [<ffffffff81177a1c>] ? shrink_dentry_list+0x5c/0x430
> [ 5954.064014] [<ffffffff81b19d86>] _raw_spin_lock+0x36/0x70
> [ 5954.064014] [<ffffffff81177a1c>] ? shrink_dentry_list+0x5c/0x430
> [ 5954.064014] [<ffffffff81177a1c>] shrink_dentry_list+0x5c/0x430
> [ 5954.064014] [<ffffffff811779c0>] ? shrink_dentry_list+0x0/0x430
> [ 5954.064014] [<ffffffff816b9c7e>] ? do_raw_spin_unlock+0x5e/0xb0
> [ 5954.064014] [<ffffffff81177f2d>] __shrink_dcache_sb+0x13d/0x1c0
> [ 5954.064014] [<ffffffff811784bf>] shrink_dcache_parent+0x32f/0x390
> [ 5954.064014] [<ffffffff8116d31d>] dentry_unhash+0x3d/0x70
> [ 5954.064014] [<ffffffff8116d3b0>] vfs_rmdir+0x60/0xe0
> [ 5954.064014] [<ffffffff8116f673>] do_rmdir+0x113/0x130
> [ 5954.064014] [<ffffffff8103a03a>] ? sysret_check+0x2e/0x69
> [ 5954.064014] [<ffffffff81b19ae9>] ? trace_hardirqs_on_thunk+0x3a/0x3f
> [ 5954.064014] [<ffffffff8116f6c5>] sys_unlinkat+0x35/0x40
> [ 5954.064014] [<ffffffff8103a002>] system_call_fastpath+0x16/0x1b
next prev parent reply other threads:[~2010-12-07 16:23 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 [this message]
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
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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