4.7-rc1: lockdep: inconsistent lock state kcompactd/aio_migratepage/mem_cgroup_migrate....
Subsystems (3)
Has anyone seen this before?
[ 335.384657] =================================
[ 335.384659] [ INFO: inconsistent lock state ]
[ 335.384663] 4.7.0-rc1+ #52 Tainted: G W
[ 335.384666] ---------------------------------
[ 335.384669] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[ 335.384672] kcompactd0/151 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 335.384674] (&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8
[ 335.384692] {IN-SOFTIRQ-W} state was registered at:
[ 335.384696] [<00000000001a8366>] __lock_acquire+0x5b6/0x1930
[ 335.384704] [<00000000001a9b9e>] lock_acquire+0xee/0x270
[ 335.384708] [<0000000000951fee>] _raw_spin_lock_irqsave+0x66/0xb0
[ 335.384717] [<0000000000390108>] aio_complete+0x98/0x328
[ 335.384721] [<000000000037c7d4>] dio_complete+0xe4/0x1e0
[ 335.384728] [<0000000000650e64>] blk_update_request+0xd4/0x450
[ 335.384736] [<000000000072a1a8>] scsi_end_request+0x48/0x1c8
[ 335.384743] [<000000000072d7e2>] scsi_io_completion+0x272/0x698
[ 335.384747] [<000000000065adb2>] blk_done_softirq+0xca/0xe8
[ 335.384753] [<0000000000953f80>] __do_softirq+0xc8/0x518
[ 335.384757] [<00000000001495de>] irq_exit+0xee/0x110
[ 335.384764] [<000000000010ceba>] do_IRQ+0x6a/0x88
[ 335.384769] [<000000000095342e>] io_int_handler+0x11a/0x25c
[ 335.384774] [<000000000094fb5c>] __mutex_unlock_slowpath+0x144/0x1d8
[ 335.384778] [<000000000094fb58>] __mutex_unlock_slowpath+0x140/0x1d8
[ 335.384783] [<00000000003c6114>] kernfs_iop_permission+0x64/0x80
[ 335.384791] [<000000000033ba86>] __inode_permission+0x9e/0xf0
[ 335.384799] [<000000000033ea96>] link_path_walk+0x6e/0x510
[ 335.384825] [<000000000033f09c>] path_lookupat+0xc4/0x1a8
[ 335.384828] [<000000000034195c>] filename_lookup+0x9c/0x160
[ 335.384831] [<0000000000341b44>] user_path_at_empty+0x5c/0x70
[ 335.384834] [<0000000000335250>] SyS_readlinkat+0x68/0x140
[ 335.384838] [<0000000000952f8e>] system_call+0xd6/0x270
[ 335.384842] irq event stamp: 971410
[ 335.384844] hardirqs last enabled at (971409): [<000000000030f982>] migrate_page_move_mapping+0x3ea/0x588
[ 335.384850] hardirqs last disabled at (971410): [<0000000000951fc4>] _raw_spin_lock_irqsave+0x3c/0xb0
[ 335.384854] softirqs last enabled at (970526): [<0000000000954318>] __do_softirq+0x460/0x518
[ 335.384858] softirqs last disabled at (970519): [<00000000001495de>] irq_exit+0xee/0x110
[ 335.384862]
other info that might help us debug this:
[ 335.384864] Possible unsafe locking scenario:[ 335.384867] CPU0
[ 335.384870] ----
[ 335.384871] lock(&(&ctx->completion_lock)->rlock);
[ 335.384875] <Interrupt>
[ 335.384877] lock(&(&ctx->completion_lock)->rlock);
[ 335.384882]
*** DEADLOCK ***[ 335.384885] 3 locks held by kcompactd0/151:
[ 335.384886] #0: (&(&mapping->private_lock)->rlock){+.+.-.}, at: [<000000000038fc82>] aio_migratepage+0x42/0x1e8
[ 335.384895] #1: (&ctx->ring_lock){+.+.+.}, at: [<000000000038fc9a>] aio_migratepage+0x5a/0x1e8
[ 335.384902] #2: (&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8
[ 335.384910]
stack backtrace:
[ 335.384913] CPU: 20 PID: 151 Comm: kcompactd0 Tainted: G W 4.7.0-rc1+ #52
[ 335.384915] 00000001c6cbb730 00000001c6cbb7c0 0000000000000002 0000000000000000
00000001c6cbb860 00000001c6cbb7d8 00000001c6cbb7d8 0000000000114496
0000000000000000 0000000000b517ec 0000000000b680b6 000000000000000b
00000001c6cbb820 00000001c6cbb7c0 0000000000000000 0000000000000000
040000000184ad18 0000000000114496 00000001c6cbb7c0 00000001c6cbb820
[ 335.384945] Call Trace:
[ 335.384950] ([<00000000001143d2>] show_trace+0xea/0xf0)
[ 335.384953] ([<000000000011444a>] show_stack+0x72/0xf0)
[ 335.384959] ([<0000000000684522>] dump_stack+0x9a/0xd8)
[ 335.384963] ([<000000000028679c>] print_usage_bug.part.27+0x2d4/0x2e8)
[ 335.384966] ([<00000000001a71ce>] mark_lock+0x17e/0x758)
[ 335.384969] ([<00000000001a784a>] mark_held_locks+0xa2/0xd0)
[ 335.384972] ([<00000000001a79b8>] trace_hardirqs_on_caller+0x140/0x1c0)
[ 335.384977] ([<0000000000326026>] mem_cgroup_migrate+0x266/0x370)
[ 335.384980] ([<000000000038fdaa>] aio_migratepage+0x16a/0x1e8)
[ 335.384982] ([<0000000000310568>] move_to_new_page+0xb0/0x260)
[ 335.384986] ([<00000000003111b4>] migrate_pages+0x8f4/0x9f0)
[ 335.384990] ([<00000000002c507c>] compact_zone+0x4dc/0xdc8)
[ 335.384992] ([<00000000002c5e22>] kcompactd_do_work+0x1aa/0x358)
[ 335.384994] ([<00000000002c608a>] kcompactd+0xba/0x2c8)
[ 335.384999] ([<000000000016b09a>] kthread+0x10a/0x110)
[ 335.385001] ([<000000000095315a>] kernel_thread_starter+0x6/0xc)
[ 335.385003] ([<0000000000953154>] kernel_thread_starter+0x0/0xc)
[ 335.385004] INFO: lockdep is turned off.--
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Tejun Heo
maintainerPATCH 1/1 memcg: mem_cgroup_migrate() may be called with irq disabled
Hello,
Christian, I *think* this should fix it. Can you please verify?
Thanks!
------ 8< ------mem_cgroup_migrate() uses local_irq_disable/enable() but can be called with irq disabled from migrate_page_copy(). This ends up enabling irq while holding a irq context lock triggering the following lockdep warning. Fix it by using irq_save/restore instead.
=================================
[ INFO: inconsistent lock state ]
4.7.0-rc1+ #52 Tainted: G W
---------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
kcompactd0/151 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8
{IN-SOFTIRQ-W} state was registered at:
[<00000000001a8366>] __lock_acquire+0x5b6/0x1930
[<00000000001a9b9e>] lock_acquire+0xee/0x270
[<0000000000951fee>] _raw_spin_lock_irqsave+0x66/0xb0
[<0000000000390108>] aio_complete+0x98/0x328
[<000000000037c7d4>] dio_complete+0xe4/0x1e0
[<0000000000650e64>] blk_update_request+0xd4/0x450
[<000000000072a1a8>] scsi_end_request+0x48/0x1c8
[<000000000072d7e2>] scsi_io_completion+0x272/0x698
[<000000000065adb2>] blk_done_softirq+0xca/0xe8
[<0000000000953f80>] __do_softirq+0xc8/0x518
[<00000000001495de>] irq_exit+0xee/0x110
[<000000000010ceba>] do_IRQ+0x6a/0x88
[<000000000095342e>] io_int_handler+0x11a/0x25c
[<000000000094fb5c>] __mutex_unlock_slowpath+0x144/0x1d8
[<000000000094fb58>] __mutex_unlock_slowpath+0x140/0x1d8
[<00000000003c6114>] kernfs_iop_permission+0x64/0x80
[<000000000033ba86>] __inode_permission+0x9e/0xf0
[<000000000033ea96>] link_path_walk+0x6e/0x510
[<000000000033f09c>] path_lookupat+0xc4/0x1a8
[<000000000034195c>] filename_lookup+0x9c/0x160
[<0000000000341b44>] user_path_at_empty+0x5c/0x70
[<0000000000335250>] SyS_readlinkat+0x68/0x140
[<0000000000952f8e>] system_call+0xd6/0x270
irq event stamp: 971410
hardirqs last enabled at (971409): [<000000000030f982>] migrate_page_move_mapping+0x3ea/0x588
hardirqs last disabled at (971410): [<0000000000951fc4>] _raw_spin_lock_irqsave+0x3c/0xb0
softirqs last enabled at (970526): [<0000000000954318>] __do_softirq+0x460/0x518
softirqs last disabled at (970519): [<00000000001495de>] irq_exit+0xee/0x110other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(&ctx->completion_lock)->rlock);
<Interrupt>
lock(&(&ctx->completion_lock)->rlock);
*** DEADLOCK ***3 locks held by kcompactd0/151:
#0: (&(&mapping->private_lock)->rlock){+.+.-.}, at: [<000000000038fc82>] aio_migratepage+0x42/0x1e8
#1: (&ctx->ring_lock){+.+.+.}, at: [<000000000038fc9a>] aio_migratepage+0x5a/0x1e8
#2: (&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8stack backtrace: CPU: 20 PID: 151 Comm: kcompactd0 Tainted: G W 4.7.0-rc1+ #52 00000001c6cbb730 00000001c6cbb7c0 0000000000000002 0000000000000000 00000001c6cbb860 00000001c6cbb7d8 00000001c6cbb7d8 0000000000114496 0000000000000000 0000000000b517ec 0000000000b680b6 000000000000000b 00000001c6cbb820 00000001c6cbb7c0 0000000000000000 0000000000000000 040000000184ad18 0000000000114496 00000001c6cbb7c0 00000001c6cbb820 Call Trace: ([<00000000001143d2>] show_trace+0xea/0xf0) ([<000000000011444a>] show_stack+0x72/0xf0) ([<0000000000684522>] dump_stack+0x9a/0xd8) ([<000000000028679c>] print_usage_bug.part.27+0x2d4/0x2e8) ([<00000000001a71ce>] mark_lock+0x17e/0x758) ([<00000000001a784a>] mark_held_locks+0xa2/0xd0) ([<00000000001a79b8>] trace_hardirqs_on_caller+0x140/0x1c0) ([<0000000000326026>] mem_cgroup_migrate+0x266/0x370) ([<000000000038fdaa>] aio_migratepage+0x16a/0x1e8) ([<0000000000310568>] move_to_new_page+0xb0/0x260) ([<00000000003111b4>] migrate_pages+0x8f4/0x9f0) ([<00000000002c507c>] compact_zone+0x4dc/0xdc8) ([<00000000002c5e22>] kcompactd_do_work+0x1aa/0x358) ([<00000000002c608a>] kcompactd+0xba/0x2c8) ([<000000000016b09a>] kthread+0x10a/0x110) ([<000000000095315a>] kernel_thread_starter+0x6/0xc) ([<0000000000953154>] kernel_thread_starter+0x0/0xc) INFO: lockdep is turned off.
Signed-off-by Tejun Heo <[email protected]>
Reported-by Christian Borntraeger <[email protected]>
--- mm/memcontrol.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
mm/memcontrol.c +3 -2
@@ -5544,6 +5544,7 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)struct mem_cgroup *memcg;unsigned int nr_pages;bool compound; +unsigned long flags;VM_BUG_ON_PAGE (!PageLocked (oldpage), oldpage);VM_BUG_ON_PAGE (!PageLocked (newpage), newpage);
@@ -5574,10 +5575,10 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)commit_charge (newpage, memcg, false); -local_irq_disable (); +local_irq_save (flags);mem_cgroup_charge_statistics (memcg, newpage, compound, nr_pages);memcg_check_events (memcg, newpage); -local_irq_enable (); +local_irq_restore (flags); }DEFINE_STATIC_KEY_FALSE (memcg_sockets_enabled_key);
--
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Re: [PATCH] memcg: mem_cgroup_migrate() may be called with irq disabled
Quoted 4 lines · Tejun Heo
mem_cgroup_migrate()uses local_irq_disable/enable() but can be called with irq disabled frommigrate_page_copy(). This ends up enabling irq while holding a irq context lock triggering the following lockdep warning. Fix it by using irq_save/restore instead.
Acked-by Johannes Weiner <[email protected]>
Fixes 74485cf2bc85 ("mm: migrate: consolidate mem_cgroup_migrate() calls")
CC [email protected] # 4.5
--
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Re: [PATCH] memcg: mem_cgroup_migrate() may be called with irq disabled
In reply to Tejun HeoQuoted 3 lines · Tejun Heo
Hello,
Christian, I *think* this should fix it. Can you please verify?
I cannot reliably reproduce the bug :-/,but at least I have not seen it with this patch and the patch makes sense and matches the traces.
Quoted 111 lines
Thanks!
------ 8< ------mem_cgroup_migrate()uses local_irq_disable/enable() but can be called with irq disabled frommigrate_page_copy(). This ends up enabling irq while holding a irq context lock triggering the following lockdep warning. Fix it by using irq_save/restore instead.=================================
[ INFO: inconsistent lock state ]
4.7.0-rc1+ #52 Tainted: G W
---------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kcompactd0/151 [HC0[0]:SC0[0]:HE1:SE1] takes:(&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8 {IN-SOFTIRQ-W} state was registered at: [<00000000001a8366>] __lock_acquire+0x5b6/0x1930 [<00000000001a9b9e>] lock_acquire+0xee/0x270 [<0000000000951fee>] _raw_spin_lock_irqsave+0x66/0xb0 [<0000000000390108>] aio_complete+0x98/0x328 [<000000000037c7d4>] dio_complete+0xe4/0x1e0 [<0000000000650e64>] blk_update_request+0xd4/0x450 [<000000000072a1a8>] scsi_end_request+0x48/0x1c8 [<000000000072d7e2>] scsi_io_completion+0x272/0x698 [<000000000065adb2>] blk_done_softirq+0xca/0xe8 [<0000000000953f80>] __do_softirq+0xc8/0x518 [<00000000001495de>] irq_exit+0xee/0x110 [<000000000010ceba>] do_IRQ+0x6a/0x88 [<000000000095342e>] io_int_handler+0x11a/0x25c [<000000000094fb5c>] __mutex_unlock_slowpath+0x144/0x1d8 [<000000000094fb58>] __mutex_unlock_slowpath+0x140/0x1d8 [<00000000003c6114>] kernfs_iop_permission+0x64/0x80 [<000000000033ba86>] __inode_permission+0x9e/0xf0 [<000000000033ea96>] link_path_walk+0x6e/0x510 [<000000000033f09c>] path_lookupat+0xc4/0x1a8 [<000000000034195c>] filename_lookup+0x9c/0x160 [<0000000000341b44>] user_path_at_empty+0x5c/0x70 [<0000000000335250>] SyS_readlinkat+0x68/0x140 [<0000000000952f8e>] system_call+0xd6/0x270 irq event stamp: 971410 hardirqs last enabled at (971409): [<000000000030f982>] migrate_page_move_mapping+0x3ea/0x588 hardirqs last disabled at (971410): [<0000000000951fc4>] _raw_spin_lock_irqsave+0x3c/0xb0 softirqs last enabled at (970526): [<0000000000954318>] __do_softirq+0x460/0x518 softirqs last disabled at (970519): [<00000000001495de>] irq_exit+0xee/0x110other info that might help us debug this:
Possible unsafe locking scenario:CPU0 ---- lock(&(&ctx->completion_lock)->rlock); <Interrupt> lock(&(&ctx->completion_lock)->rlock); *** DEADLOCK ***3 locks held by kcompactd0/151:
#0: (&(&mapping->private_lock)->rlock){+.+.-.}, at: [<000000000038fc82>] aio_migratepage+0x42/0x1e8 #1: (&ctx->ring_lock){+.+.+.}, at: [<000000000038fc9a>] aio_migratepage+0x5a/0x1e8 #2: (&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8stack backtrace: CPU: 20 PID: 151 Comm: kcompactd0 Tainted: G W 4.7.0-rc1+ #52 00000001c6cbb730 00000001c6cbb7c0 0000000000000002 0000000000000000 00000001c6cbb860 00000001c6cbb7d8 00000001c6cbb7d8 0000000000114496 0000000000000000 0000000000b517ec 0000000000b680b6 000000000000000b 00000001c6cbb820 00000001c6cbb7c0 0000000000000000 0000000000000000 040000000184ad18 0000000000114496 00000001c6cbb7c0 00000001c6cbb820 Call Trace: ([<00000000001143d2>] show_trace+0xea/0xf0) ([<000000000011444a>] show_stack+0x72/0xf0) ([<0000000000684522>] dump_stack+0x9a/0xd8) ([<000000000028679c>] print_usage_bug.part.27+0x2d4/0x2e8) ([<00000000001a71ce>] mark_lock+0x17e/0x758) ([<00000000001a784a>] mark_held_locks+0xa2/0xd0) ([<00000000001a79b8>] trace_hardirqs_on_caller+0x140/0x1c0) ([<0000000000326026>] mem_cgroup_migrate+0x266/0x370) ([<000000000038fdaa>] aio_migratepage+0x16a/0x1e8) ([<0000000000310568>] move_to_new_page+0xb0/0x260) ([<00000000003111b4>] migrate_pages+0x8f4/0x9f0) ([<00000000002c507c>] compact_zone+0x4dc/0xdc8) ([<00000000002c5e22>] kcompactd_do_work+0x1aa/0x358) ([<00000000002c608a>] kcompactd+0xba/0x2c8) ([<000000000016b09a>] kthread+0x10a/0x110) ([<000000000095315a>] kernel_thread_starter+0x6/0xc) ([<0000000000953154>] kernel_thread_starter+0x0/0xc) INFO: lockdep is turned off.Signed-off-by Tejun Heo <[email protected]>Reported-by Christian Borntraeger <[email protected]>--- mm/memcontrol.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)mm/memcontrol.c +1
-0@@ -5544,6 +5544,7 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)struct mem_cgroup *memcg;unsigned int nr_pages;bool compound; +unsigned long flags;VM_BUG_ON_PAGE (!PageLocked (oldpage), oldpage);VM_BUG_ON_PAGE (!PageLocked (newpage), newpage);@@ -5574,10 +5575,10 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)commit_charge (newpage, memcg, false);
mm/memcontrol.c void mem_cgroup_migrate(struct page *oldpage, struct page *newpage) · line 5584
Quoted 10 lines
mm/memcontrol.c +2
-2-local_irq_disable (); +local_irq_save (flags);mem_cgroup_charge_statistics (memcg, newpage, compound, nr_pages);memcg_check_events (memcg, newpage); -local_irq_enable (); +local_irq_restore (flags); }DEFINE_STATIC_KEY_FALSE (memcg_sockets_enabled_key);
--
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Re: [PATCH] memcg: mem_cgroup_migrate() may be called with irq disabled
In reply to Tejun HeoQuoted 91 lines · Tejun Heo
Hello,
Christian, I *think* this should fix it. Can you please verify?
Thanks!
------ 8< ------mem_cgroup_migrate()uses local_irq_disable/enable() but can be called with irq disabled frommigrate_page_copy(). This ends up enabling irq while holding a irq context lock triggering the following lockdep warning. Fix it by using irq_save/restore instead.=================================
[ INFO: inconsistent lock state ]
4.7.0-rc1+ #52 Tainted: G W
---------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kcompactd0/151 [HC0[0]:SC0[0]:HE1:SE1] takes:(&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8 {IN-SOFTIRQ-W} state was registered at: [<00000000001a8366>] __lock_acquire+0x5b6/0x1930 [<00000000001a9b9e>] lock_acquire+0xee/0x270 [<0000000000951fee>] _raw_spin_lock_irqsave+0x66/0xb0 [<0000000000390108>] aio_complete+0x98/0x328 [<000000000037c7d4>] dio_complete+0xe4/0x1e0 [<0000000000650e64>] blk_update_request+0xd4/0x450 [<000000000072a1a8>] scsi_end_request+0x48/0x1c8 [<000000000072d7e2>] scsi_io_completion+0x272/0x698 [<000000000065adb2>] blk_done_softirq+0xca/0xe8 [<0000000000953f80>] __do_softirq+0xc8/0x518 [<00000000001495de>] irq_exit+0xee/0x110 [<000000000010ceba>] do_IRQ+0x6a/0x88 [<000000000095342e>] io_int_handler+0x11a/0x25c [<000000000094fb5c>] __mutex_unlock_slowpath+0x144/0x1d8 [<000000000094fb58>] __mutex_unlock_slowpath+0x140/0x1d8 [<00000000003c6114>] kernfs_iop_permission+0x64/0x80 [<000000000033ba86>] __inode_permission+0x9e/0xf0 [<000000000033ea96>] link_path_walk+0x6e/0x510 [<000000000033f09c>] path_lookupat+0xc4/0x1a8 [<000000000034195c>] filename_lookup+0x9c/0x160 [<0000000000341b44>] user_path_at_empty+0x5c/0x70 [<0000000000335250>] SyS_readlinkat+0x68/0x140 [<0000000000952f8e>] system_call+0xd6/0x270 irq event stamp: 971410 hardirqs last enabled at (971409): [<000000000030f982>] migrate_page_move_mapping+0x3ea/0x588 hardirqs last disabled at (971410): [<0000000000951fc4>] _raw_spin_lock_irqsave+0x3c/0xb0 softirqs last enabled at (970526): [<0000000000954318>] __do_softirq+0x460/0x518 softirqs last disabled at (970519): [<00000000001495de>] irq_exit+0xee/0x110other info that might help us debug this:
Possible unsafe locking scenario:CPU0 ---- lock(&(&ctx->completion_lock)->rlock); <Interrupt> lock(&(&ctx->completion_lock)->rlock); *** DEADLOCK ***3 locks held by kcompactd0/151:
#0: (&(&mapping->private_lock)->rlock){+.+.-.}, at: [<000000000038fc82>] aio_migratepage+0x42/0x1e8 #1: (&ctx->ring_lock){+.+.+.}, at: [<000000000038fc9a>] aio_migratepage+0x5a/0x1e8 #2: (&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8stack backtrace: CPU: 20 PID: 151 Comm: kcompactd0 Tainted: G W 4.7.0-rc1+ #52 00000001c6cbb730 00000001c6cbb7c0 0000000000000002 0000000000000000 00000001c6cbb860 00000001c6cbb7d8 00000001c6cbb7d8 0000000000114496 0000000000000000 0000000000b517ec 0000000000b680b6 000000000000000b 00000001c6cbb820 00000001c6cbb7c0 0000000000000000 0000000000000000 040000000184ad18 0000000000114496 00000001c6cbb7c0 00000001c6cbb820 Call Trace: ([<00000000001143d2>] show_trace+0xea/0xf0) ([<000000000011444a>] show_stack+0x72/0xf0) ([<0000000000684522>] dump_stack+0x9a/0xd8) ([<000000000028679c>] print_usage_bug.part.27+0x2d4/0x2e8) ([<00000000001a71ce>] mark_lock+0x17e/0x758) ([<00000000001a784a>] mark_held_locks+0xa2/0xd0) ([<00000000001a79b8>] trace_hardirqs_on_caller+0x140/0x1c0) ([<0000000000326026>] mem_cgroup_migrate+0x266/0x370) ([<000000000038fdaa>] aio_migratepage+0x16a/0x1e8) ([<0000000000310568>] move_to_new_page+0xb0/0x260) ([<00000000003111b4>] migrate_pages+0x8f4/0x9f0) ([<00000000002c507c>] compact_zone+0x4dc/0xdc8) ([<00000000002c5e22>] kcompactd_do_work+0x1aa/0x358) ([<00000000002c608a>] kcompactd+0xba/0x2c8) ([<000000000016b09a>] kthread+0x10a/0x110) ([<000000000095315a>] kernel_thread_starter+0x6/0xc) ([<0000000000953154>] kernel_thread_starter+0x0/0xc) INFO: lockdep is turned off.
Quoted 3 lines
Signed-off-by Tejun Heo <[email protected]>Reported-by Christian Borntraeger <[email protected]>
Acked-by Michal Hocko <[email protected]>
Quoted 29 lines
--- mm/memcontrol.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)mm/memcontrol.c +3
-2@@ -5544,6 +5544,7 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)struct mem_cgroup *memcg;unsigned int nr_pages;bool compound; +unsigned long flags;VM_BUG_ON_PAGE (!PageLocked (oldpage), oldpage);VM_BUG_ON_PAGE (!PageLocked (newpage), newpage);@@ -5574,10 +5575,10 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)commit_charge (newpage, memcg, false); -local_irq_disable (); +local_irq_save (flags);mem_cgroup_charge_statistics (memcg, newpage, compound, nr_pages);memcg_check_events (memcg, newpage); -local_irq_enable (); +local_irq_restore (flags); }DEFINE_STATIC_KEY_FALSE (memcg_sockets_enabled_key);
Signature · 8 lines
Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"[email protected]"> [email protected] </a>
Re: [PATCH] memcg: mem_cgroup_migrate() may be called with irq disabled
In reply to Tejun HeoQuoted 85 lines · Tejun Heo
mem_cgroup_migrate()uses local_irq_disable/enable() but can be called with irq disabled frommigrate_page_copy(). This ends up enabling irq while holding a irq context lock triggering the following lockdep warning. Fix it by using irq_save/restore instead.=================================
[ INFO: inconsistent lock state ]
4.7.0-rc1+ #52 Tainted: G W
---------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kcompactd0/151 [HC0[0]:SC0[0]:HE1:SE1] takes:(&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8 {IN-SOFTIRQ-W} state was registered at: [<00000000001a8366>] __lock_acquire+0x5b6/0x1930 [<00000000001a9b9e>] lock_acquire+0xee/0x270 [<0000000000951fee>] _raw_spin_lock_irqsave+0x66/0xb0 [<0000000000390108>] aio_complete+0x98/0x328 [<000000000037c7d4>] dio_complete+0xe4/0x1e0 [<0000000000650e64>] blk_update_request+0xd4/0x450 [<000000000072a1a8>] scsi_end_request+0x48/0x1c8 [<000000000072d7e2>] scsi_io_completion+0x272/0x698 [<000000000065adb2>] blk_done_softirq+0xca/0xe8 [<0000000000953f80>] __do_softirq+0xc8/0x518 [<00000000001495de>] irq_exit+0xee/0x110 [<000000000010ceba>] do_IRQ+0x6a/0x88 [<000000000095342e>] io_int_handler+0x11a/0x25c [<000000000094fb5c>] __mutex_unlock_slowpath+0x144/0x1d8 [<000000000094fb58>] __mutex_unlock_slowpath+0x140/0x1d8 [<00000000003c6114>] kernfs_iop_permission+0x64/0x80 [<000000000033ba86>] __inode_permission+0x9e/0xf0 [<000000000033ea96>] link_path_walk+0x6e/0x510 [<000000000033f09c>] path_lookupat+0xc4/0x1a8 [<000000000034195c>] filename_lookup+0x9c/0x160 [<0000000000341b44>] user_path_at_empty+0x5c/0x70 [<0000000000335250>] SyS_readlinkat+0x68/0x140 [<0000000000952f8e>] system_call+0xd6/0x270 irq event stamp: 971410 hardirqs last enabled at (971409): [<000000000030f982>] migrate_page_move_mapping+0x3ea/0x588 hardirqs last disabled at (971410): [<0000000000951fc4>] _raw_spin_lock_irqsave+0x3c/0xb0 softirqs last enabled at (970526): [<0000000000954318>] __do_softirq+0x460/0x518 softirqs last disabled at (970519): [<00000000001495de>] irq_exit+0xee/0x110other info that might help us debug this:
Possible unsafe locking scenario:CPU0 ---- lock(&(&ctx->completion_lock)->rlock); <Interrupt> lock(&(&ctx->completion_lock)->rlock); *** DEADLOCK ***3 locks held by kcompactd0/151:
#0: (&(&mapping->private_lock)->rlock){+.+.-.}, at: [<000000000038fc82>] aio_migratepage+0x42/0x1e8 #1: (&ctx->ring_lock){+.+.+.}, at: [<000000000038fc9a>] aio_migratepage+0x5a/0x1e8 #2: (&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8stack backtrace: CPU: 20 PID: 151 Comm: kcompactd0 Tainted: G W 4.7.0-rc1+ #52 00000001c6cbb730 00000001c6cbb7c0 0000000000000002 0000000000000000 00000001c6cbb860 00000001c6cbb7d8 00000001c6cbb7d8 0000000000114496 0000000000000000 0000000000b517ec 0000000000b680b6 000000000000000b 00000001c6cbb820 00000001c6cbb7c0 0000000000000000 0000000000000000 040000000184ad18 0000000000114496 00000001c6cbb7c0 00000001c6cbb820 Call Trace: ([<00000000001143d2>] show_trace+0xea/0xf0) ([<000000000011444a>] show_stack+0x72/0xf0) ([<0000000000684522>] dump_stack+0x9a/0xd8) ([<000000000028679c>] print_usage_bug.part.27+0x2d4/0x2e8) ([<00000000001a71ce>] mark_lock+0x17e/0x758) ([<00000000001a784a>] mark_held_locks+0xa2/0xd0) ([<00000000001a79b8>] trace_hardirqs_on_caller+0x140/0x1c0) ([<0000000000326026>] mem_cgroup_migrate+0x266/0x370) ([<000000000038fdaa>] aio_migratepage+0x16a/0x1e8) ([<0000000000310568>] move_to_new_page+0xb0/0x260) ([<00000000003111b4>] migrate_pages+0x8f4/0x9f0) ([<00000000002c507c>] compact_zone+0x4dc/0xdc8) ([<00000000002c5e22>] kcompactd_do_work+0x1aa/0x358) ([<00000000002c608a>] kcompactd+0xba/0x2c8) ([<000000000016b09a>] kthread+0x10a/0x110) ([<000000000095315a>] kernel_thread_starter+0x6/0xc) ([<0000000000953154>] kernel_thread_starter+0x0/0xc) INFO: lockdep is turned off.
Quoted 3 lines
Signed-off-by Tejun Heo <[email protected]>Reported-by Christian Borntraeger <[email protected]>
Reviewed-by Vladimir Davydov <[email protected]>
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