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author | Gavin Shan <shangw@linux.vnet.ibm.com> | 2012-10-25 20:38:01 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-25 21:37:53 (GMT) |
commit | 35cfa2b0b491c37e23527822bf365610dbb188e5 (patch) | |
tree | 6ed3462dbfa3d9e2bc124b03e290e497e503b12e /drivers/dma | |
parent | fc314d0a4a933603f521de343634910a4ed9b37b (diff) | |
download | linux-35cfa2b0b491c37e23527822bf365610dbb188e5.tar.xz |
mm/mmu_notifier: allocate mmu_notifier in advance
While allocating mmu_notifier with parameter GFP_KERNEL, swap would start
to work in case of tight available memory. Eventually, that would lead to
a deadlock while the swap deamon swaps anonymous pages. It was caused by
commit e0f3c3f78da29b ("mm/mmu_notifier: init notifier if necessary").
=================================
[ INFO: inconsistent lock state ]
3.7.0-rc1+ #518 Not tainted
---------------------------------
inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
kswapd0/35 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&mapping->i_mmap_mutex){+.+.?.}, at: page_referenced+0x9c/0x2e0
{RECLAIM_FS-ON-W} state was registered at:
mark_held_locks+0x86/0x150
lockdep_trace_alloc+0x67/0xc0
kmem_cache_alloc_trace+0x33/0x230
do_mmu_notifier_register+0x87/0x180
mmu_notifier_register+0x13/0x20
kvm_dev_ioctl+0x428/0x510
do_vfs_ioctl+0x98/0x570
sys_ioctl+0x91/0xb0
system_call_fastpath+0x16/0x1b
irq event stamp: 825
hardirqs last enabled at (825): _raw_spin_unlock_irq+0x30/0x60
hardirqs last disabled at (824): _raw_spin_lock_irq+0x19/0x80
softirqs last enabled at (0): copy_process+0x630/0x17c0
softirqs last disabled at (0): (null)
...
Simply back out the above commit, which was a small performance
optimization.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Reported-by: Andrea Righi <andrea@betterlinux.com>
Tested-by: Andrea Righi <andrea@betterlinux.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Sagi Grimberg <sagig@mellanox.co.il>
Cc: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/dma')
0 files changed, 0 insertions, 0 deletions