tree fd0fa107c4b85649722b9921a4bcdb35776eb36f
parent a189d0350f387786b1fb5a5d19e3a5ab0bc0cceb
author KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> 1226525213 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1226539036 -0800

mm: remove lru_add_drain_all() from the munlock path

lockdep warns about following message at boot time on one of my test
machine.  Then, schedule_on_each_cpu() sholdn't be called when the task
have mmap_sem.

Actually, lru_add_drain_all() exist to prevent the unevictalble pages
stay on reclaimable lru list.  but currenct unevictable code can rescue
unevictable pages although it stay on reclaimable list.

So removing is better.

In addition, this patch add lru_add_drain_all() to sys_mlock() and
sys_mlockall().  it isn't must.  but it reduce the failure of moving to
unevictable list.  its failure can rescue in vmscan later.  but reducing
is better.

Note, if above rescuing happend, the Mlocked and the Unevictable field
mismatching happend in /proc/meminfo.  but it doesn't cause any real
trouble.

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.28-rc2-mm1 #2
-------------------------------------------------------
lvm/1103 is trying to acquire lock:
 (&cpu_hotplug.lock){--..}, at: [<c0130789>] get_online_cpus+0x29/0x50

but task is already holding lock:
 (&mm->mmap_sem){----}, at: [<c01878ae>] sys_mlockall+0x4e/0xb0

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (&mm->mmap_sem){----}:
       [<c0153da2>] check_noncircular+0x82/0x110
       [<c0185e6a>] might_fault+0x4a/0xa0
       [<c0156161>] validate_chain+0xb11/0x1070
       [<c0185e6a>] might_fault+0x4a/0xa0
       [<c0156923>] __lock_acquire+0x263/0xa10
       [<c015714c>] lock_acquire+0x7c/0xb0			(*) grab mmap_sem
       [<c0185e6a>] might_fault+0x4a/0xa0
       [<c0185e9b>] might_fault+0x7b/0xa0
       [<c0185e6a>] might_fault+0x4a/0xa0
       [<c0294dd0>] copy_to_user+0x30/0x60
       [<c01ae3ec>] filldir+0x7c/0xd0
       [<c01e3a6a>] sysfs_readdir+0x11a/0x1f0			(*) grab sysfs_mutex
       [<c01ae370>] filldir+0x0/0xd0
       [<c01ae370>] filldir+0x0/0xd0
       [<c01ae4c6>] vfs_readdir+0x86/0xa0			(*) grab i_mutex
       [<c01ae75b>] sys_getdents+0x6b/0xc0
       [<c010355a>] syscall_call+0x7/0xb
       [<ffffffff>] 0xffffffff

-> #2 (sysfs_mutex){--..}:
       [<c0153da2>] check_noncircular+0x82/0x110
       [<c01e3d2c>] sysfs_addrm_start+0x2c/0xc0
       [<c0156161>] validate_chain+0xb11/0x1070
       [<c01e3d2c>] sysfs_addrm_start+0x2c/0xc0
       [<c0156923>] __lock_acquire+0x263/0xa10
       [<c015714c>] lock_acquire+0x7c/0xb0			(*) grab sysfs_mutex
       [<c01e3d2c>] sysfs_addrm_start+0x2c/0xc0
       [<c04f8b55>] mutex_lock_nested+0xa5/0x2f0
       [<c01e3d2c>] sysfs_addrm_start+0x2c/0xc0
       [<c01e3d2c>] sysfs_addrm_start+0x2c/0xc0
       [<c01e3d2c>] sysfs_addrm_start+0x2c/0xc0
       [<c01e422f>] create_dir+0x3f/0x90
       [<c01e42a9>] sysfs_create_dir+0x29/0x50
       [<c04faaf5>] _spin_unlock+0x25/0x40
       [<c028f21d>] kobject_add_internal+0xcd/0x1a0
       [<c028f37a>] kobject_set_name_vargs+0x3a/0x50
       [<c028f41d>] kobject_init_and_add+0x2d/0x40
       [<c019d4d2>] sysfs_slab_add+0xd2/0x180
       [<c019d580>] sysfs_add_func+0x0/0x70
       [<c019d5dc>] sysfs_add_func+0x5c/0x70			(*) grab slub_lock
       [<c01400f2>] run_workqueue+0x172/0x200
       [<c014008f>] run_workqueue+0x10f/0x200
       [<c0140bd0>] worker_thread+0x0/0xf0
       [<c0140c6c>] worker_thread+0x9c/0xf0
       [<c0143c80>] autoremove_wake_function+0x0/0x50
       [<c0140bd0>] worker_thread+0x0/0xf0
       [<c0143972>] kthread+0x42/0x70
       [<c0143930>] kthread+0x0/0x70
       [<c01042db>] kernel_thread_helper+0x7/0x1c
       [<ffffffff>] 0xffffffff

-> #1 (slub_lock){----}:
       [<c0153d2d>] check_noncircular+0xd/0x110
       [<c04f650f>] slab_cpuup_callback+0x11f/0x1d0
       [<c0156161>] validate_chain+0xb11/0x1070
       [<c04f650f>] slab_cpuup_callback+0x11f/0x1d0
       [<c015433d>] mark_lock+0x35d/0xd00
       [<c0156923>] __lock_acquire+0x263/0xa10
       [<c015714c>] lock_acquire+0x7c/0xb0
       [<c04f650f>] slab_cpuup_callback+0x11f/0x1d0
       [<c04f93a3>] down_read+0x43/0x80
       [<c04f650f>] slab_cpuup_callback+0x11f/0x1d0		(*) grab slub_lock
       [<c04f650f>] slab_cpuup_callback+0x11f/0x1d0
       [<c04fd9ac>] notifier_call_chain+0x3c/0x70
       [<c04f5454>] _cpu_up+0x84/0x110
       [<c04f552b>] cpu_up+0x4b/0x70				(*) grab cpu_hotplug.lock
       [<c06d1530>] kernel_init+0x0/0x170
       [<c06d15e5>] kernel_init+0xb5/0x170
       [<c06d1530>] kernel_init+0x0/0x170
       [<c01042db>] kernel_thread_helper+0x7/0x1c
       [<ffffffff>] 0xffffffff

-> #0 (&cpu_hotplug.lock){--..}:
       [<c0155bff>] validate_chain+0x5af/0x1070
       [<c040f7e0>] dev_status+0x0/0x50
       [<c0156923>] __lock_acquire+0x263/0xa10
       [<c015714c>] lock_acquire+0x7c/0xb0
       [<c0130789>] get_online_cpus+0x29/0x50
       [<c04f8b55>] mutex_lock_nested+0xa5/0x2f0
       [<c0130789>] get_online_cpus+0x29/0x50
       [<c0130789>] get_online_cpus+0x29/0x50
       [<c017bc30>] lru_add_drain_per_cpu+0x0/0x10
       [<c0130789>] get_online_cpus+0x29/0x50			(*) grab cpu_hotplug.lock
       [<c0140cf2>] schedule_on_each_cpu+0x32/0xe0
       [<c0187095>] __mlock_vma_pages_range+0x85/0x2c0
       [<c0156945>] __lock_acquire+0x285/0xa10
       [<c0188f09>] vma_merge+0xa9/0x1d0
       [<c0187450>] mlock_fixup+0x180/0x200
       [<c0187548>] do_mlockall+0x78/0x90			(*) grab mmap_sem
       [<c01878e1>] sys_mlockall+0x81/0xb0
       [<c010355a>] syscall_call+0x7/0xb
       [<ffffffff>] 0xffffffff

other info that might help us debug this:

1 lock held by lvm/1103:
 #0:  (&mm->mmap_sem){----}, at: [<c01878ae>] sys_mlockall+0x4e/0xb0

stack backtrace:
Pid: 1103, comm: lvm Not tainted 2.6.28-rc2-mm1 #2
Call Trace:
 [<c01555fc>] print_circular_bug_tail+0x7c/0xd0
 [<c0155bff>] validate_chain+0x5af/0x1070
 [<c040f7e0>] dev_status+0x0/0x50
 [<c0156923>] __lock_acquire+0x263/0xa10
 [<c015714c>] lock_acquire+0x7c/0xb0
 [<c0130789>] get_online_cpus+0x29/0x50
 [<c04f8b55>] mutex_lock_nested+0xa5/0x2f0
 [<c0130789>] get_online_cpus+0x29/0x50
 [<c0130789>] get_online_cpus+0x29/0x50
 [<c017bc30>] lru_add_drain_per_cpu+0x0/0x10
 [<c0130789>] get_online_cpus+0x29/0x50
 [<c0140cf2>] schedule_on_each_cpu+0x32/0xe0
 [<c0187095>] __mlock_vma_pages_range+0x85/0x2c0
 [<c0156945>] __lock_acquire+0x285/0xa10
 [<c0188f09>] vma_merge+0xa9/0x1d0
 [<c0187450>] mlock_fixup+0x180/0x200
 [<c0187548>] do_mlockall+0x78/0x90
 [<c01878e1>] sys_mlockall+0x81/0xb0
 [<c010355a>] syscall_call+0x7/0xb

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>