The patch titled
mm: remove lru_add_drain_all() from the munlock path
has been added to the -mm tree. Its filename is
mm-remove-lru_add_drain_all-from-the-munlock-path.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mm: remove lru_add_drain_all() from the munlock path
From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
Tested-by: Kamalesh Babulal <kamalesh@xxxxxxxxxxxxxxxxxx>
Cc: Lee Schermerhorn <Lee.Schermerhorn@xxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mlock.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff -puN mm/mlock.c~mm-remove-lru_add_drain_all-from-the-munlock-path mm/mlock.c
--- a/mm/mlock.c~mm-remove-lru_add_drain_all-from-the-munlock-path
+++ a/mm/mlock.c
@@ -66,14 +66,10 @@ void __clear_page_mlock(struct page *pag
putback_lru_page(page);
} else {
/*
- * Page not on the LRU yet. Flush all pagevecs and retry.
+ * We lost the race. the page already moved to evictable list.
*/
- lru_add_drain_all();
- if (!isolate_lru_page(page))
- putback_lru_page(page);
- else if (PageUnevictable(page))
+ if (PageUnevictable(page))
count_vm_event(UNEVICTABLE_PGSTRANDED);
-
}
}
@@ -187,8 +183,6 @@ static long __mlock_vma_pages_range(stru
if (vma->vm_flags & VM_WRITE)
gup_flags |= GUP_FLAGS_WRITE;
- lru_add_drain_all(); /* push cached pages to LRU */
-
while (nr_pages > 0) {
int i;
@@ -251,8 +245,6 @@ static long __mlock_vma_pages_range(stru
ret = 0;
}
- lru_add_drain_all(); /* to update stats */
-
return ret; /* count entire vma as locked_vm */
}
@@ -546,6 +538,8 @@ asmlinkage long sys_mlock(unsigned long
if (!can_do_mlock())
return -EPERM;
+ lru_add_drain_all(); /* flush pagevec */
+
down_write(¤t->mm->mmap_sem);
len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
start &= PAGE_MASK;
@@ -612,6 +606,8 @@ asmlinkage long sys_mlockall(int flags)
if (!can_do_mlock())
goto out;
+ lru_add_drain_all(); /* flush pagevec */
+
down_write(¤t->mm->mmap_sem);
lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
_
Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are
mm-move-migrate_prep-out-from-under-mmap_sem.patch
mm-remove-lru_add_drain_all-from-the-munlock-path.patch
mm-report-the-pagesize-backing-a-vma-in-proc-pid-smaps.patch
mm-report-the-mmu-pagesize-in-proc-pid-smaps.patch
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