From: Stephen Hemminger <stephen@networkplumber.org>
To: Marcelo Tosatti <mtosatti@redhat.com>, Gleb Natapov <gleb@redhat.com>
Cc: kvm@vger.kernel.org
Subject: Locking problem in KVM (or MM)
Date: Wed, 16 Jan 2013 14:41:25 -0800 [thread overview]
Message-ID: <20130116144125.7f5a91e6@nehalam.linuxnetplumber.net> (raw)
Lockdep splat, appears to be KVM related with 3.8-rc1
[24428.429305]
[24428.429308] =============================================
[24428.429309] [ INFO: possible recursive locking detected ]
[24428.429312] 3.8.0-rc1-net-next+ #4 Tainted: G W
[24428.429312] ---------------------------------------------
[24428.429313] kvm/7355 is trying to acquire lock:
[24428.429314] (&anon_vma->rwsem){++++..}, at: [<ffffffff811373f8>] mm_take_all
_locks+0x102/0x14e
[24428.429321]
[24428.429321] but task is already holding lock:
[24428.429322] (&anon_vma->rwsem){++++..}, at: [<ffffffff811373f8>] mm_take_all
_locks+0x102/0x14e
[24428.429325]
[24428.429325] other info that might help us debug this:
[24428.429326] Possible unsafe locking scenario:
[24428.429326]
[24428.429327] CPU0
[24428.429327] ----
[24428.429328] lock(&anon_vma->rwsem);
[24428.429329] lock(&anon_vma->rwsem);
[24428.429331]
[24428.429331] *** DEADLOCK ***
[24428.429331]
[24428.429332] May be due to missing lock nesting notation
[24428.429332]
[24428.429333] 4 locks held by kvm/7355:
[24428.429334] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff81148b64>] do_mmu_no
tifier_register+0x65/0x12c
[24428.429338] #1: (mm_all_locks_mutex){+.+...}, at: [<ffffffff8113732f>] mm_t
ake_all_locks+0x39/0x14e
[24428.429341] #2: (&mapping->i_mmap_mutex){+.+...}, at: [<ffffffff81137397>]
mm_take_all_locks+0xa1/0x14e
[24428.429344] #3: (&anon_vma->rwsem){++++..}, at: [<ffffffff811373f8>] mm_tak
e_all_locks+0x102/0x14e
[24428.429347]
[24428.429347] stack backtrace:
[24428.429348] Pid: 7355, comm: kvm Tainted: G W 3.8.0-rc1-net-next+ #
4
[24428.429349] Call Trace:
[24428.429354] [<ffffffff810b82f0>] __lock_acquire+0x569/0xe12
[24428.429356] [<ffffffff810b9025>] lock_acquire+0xd7/0x123
[24428.429358] [<ffffffff811373f8>] ? mm_take_all_locks+0x102/0x14e
[24428.429361] [<ffffffff814e490a>] down_write+0x49/0x58
[24428.429363] [<ffffffff811373f8>] ? mm_take_all_locks+0x102/0x14e
[24428.429365] [<ffffffff814e44d2>] ? _mutex_lock_nest_lock+0x40/0x45
[24428.429366] [<ffffffff811373f8>] mm_take_all_locks+0x102/0x14e
[24428.429369] [<ffffffff81148b6c>] do_mmu_notifier_register+0x6d/0x12c
[24428.429371] [<ffffffff81148c50>] mmu_notifier_register+0x13/0x15
[24428.429373] [<ffffffff81004ed9>] kvm_dev_ioctl+0x277/0x3e4
[24428.429376] [<ffffffff8116471e>] vfs_ioctl+0x26/0x39
[24428.429378] [<ffffffff8116501b>] do_vfs_ioctl+0x40f/0x452
[24428.429381] [<ffffffff810f759f>] ? time_hardirqs_off+0x15/0x2a
[24428.429383] [<ffffffff814e6d63>] ? error_sti+0x5/0x6
[24428.429385] [<ffffffff810b5da0>] ? trace_hardirqs_off_caller+0x3f/0x9e
[24428.429388] [<ffffffff8116d353>] ? fget_light+0x3d/0x9d
[24428.429389] [<ffffffff811650b5>] sys_ioctl+0x57/0x86
[24428.429393] [<ffffffff812c23de>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[24428.429395] [<ffffffff814ed582>] system_call_fastpath+0x16/0x1b
next reply other threads:[~2013-01-16 22:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-16 22:41 Stephen Hemminger [this message]
2013-01-16 23:31 ` Locking problem in KVM (or MM) Marcelo Tosatti
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