From: Sasha Levin <levinsasha928@gmail.com>
To: axboe@kernel.dk, Tejun Heo <tj@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Dave Jones <davej@redhat.com>
Subject: Re: blk, mm: lockdep irq lock inversion in linux-next
Date: Sat, 15 Sep 2012 16:02:10 +0200 [thread overview]
Message-ID: <50548A62.5000005@gmail.com> (raw)
In-Reply-To: <5054878F.1030908@gmail.com>
On 09/15/2012 03:50 PM, Sasha Levin wrote:
> Hi all,
>
> While fuzzing with trinity within a KVM tools guest on a linux-next kernel, I
> got the lockdep warning at the bottom of this mail.
>
> I've tried figuring out where it was introduced, but haven't found any sign that
> any of the code in that area changed recently, so I'm probably missing something...
>
>
> [ 157.966399] =========================================================
> [ 157.968523] [ INFO: possible irq lock inversion dependency detected ]
> [ 157.970029] 3.6.0-rc5-next-20120914-sasha-00001-g802bf6c-dirty #340 Tainted: G W
> [ 157.970029] ---------------------------------------------------------
> [ 157.970029] trinity-child38/6642 just changed the state of lock:
> [ 157.970029] (&(&mapping->tree_lock)->rlock){+.+...}, at: [<ffffffff8120cafc>]
> invalidate_inode_pages2_range+0x20c/0x3c0
> [ 157.970029] but this lock was taken by another, SOFTIRQ-safe lock in the past:
> [ 157.970029] (&(&new->queue_lock)->rlock){..-...}
>
> and interrupts could create inverse lock ordering between them.
>
> [ 157.970029]
> [ 157.970029] other info that might help us debug this:
> [ 157.970029] Possible interrupt unsafe locking scenario:
> [ 157.970029]
> [ 157.970029] CPU0 CPU1
> [ 157.970029] ---- ----
> [ 157.970029] lock(&(&mapping->tree_lock)->rlock);
> [ 157.970029] local_irq_disable();
> [ 157.970029] lock(&(&new->queue_lock)->rlock);
> [ 157.970029] lock(&(&mapping->tree_lock)->rlock);
> [ 157.970029] <Interrupt>
> [ 157.970029] lock(&(&new->queue_lock)->rlock);
> [ 157.970029]
> [ 157.970029] *** DEADLOCK ***
> [ 157.970029]
> [ 157.970029] 1 lock held by trinity-child38/6642:
> [ 157.970029] #0: (&(&mapping->tree_lock)->rlock){+.+...}, at:
> [<ffffffff8120cafc>] invalidate_inode_pages2_range+0x20c/0x3c0
> [ 157.970029]
> [ 157.970029] the shortest dependencies between 2nd lock and 1st lock:
> [ 157.970029] -> (&(&new->queue_lock)->rlock){..-...} ops: 4790 {
> [ 157.970029] IN-SOFTIRQ-W at:
> [ 157.970029] [<ffffffff8117bf2a>] __lock_acquire+0x87a/0x1bd0
> [ 157.970029] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
> [ 157.970029] [<ffffffff8375f6cc>] _raw_spin_lock_irqsave+0x7c/0xc0
> [ 157.970029] [<ffffffff819b7239>] cfq_idle_slice_timer+0x19/0xd0
> [ 157.970029] [<ffffffff81119f66>] call_timer_fn+0x166/0x380
> [ 157.970029] [<ffffffff8111a46c>] run_timer_softirq+0x2ec/0x380
> [ 157.970029] [<ffffffff81110b27>] __do_softirq+0x1c7/0x440
> [ 157.970029] [<ffffffff8376256c>] call_softirq+0x1c/0x30
> [ 157.970029] [<ffffffff8106f51d>] do_softirq+0x6d/0x100
> [ 157.970029] [<ffffffff81110f1a>] irq_exit+0x5a/0xd0
> [ 157.970029] [<ffffffff8109674a>] smp_apic_timer_interrupt+0x8a/0xa0
> [ 157.970029] [<ffffffff83761e6f>] apic_timer_interrupt+0x6f/0x80
> [ 157.970029] [<ffffffff810775b5>] default_idle+0x235/0x5b0
> [ 157.970029] [<ffffffff810785e8>] cpu_idle+0x138/0x160
> [ 157.970029] [<ffffffff836fbed7>] start_secondary+0x26e/0x276
> [ 157.970029] INITIAL USE at:
> [ 157.970029] [<ffffffff8117c07f>] __lock_acquire+0x9cf/0x1bd0
> [ 157.970029] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
> [ 157.970029] [<ffffffff8375f767>] _raw_spin_lock_irq+0x57/0x90
> [ 157.970029] [<ffffffff819954e6>] blk_queue_bypass_start+0x16/0xa0
> [ 157.970029] [<ffffffff819af017>] blkcg_activate_policy+0x67/0x370
> [ 157.970029] [<ffffffff819b3d09>] cfq_init_queue+0x79/0x380
> [ 157.970029] [<ffffffff8198eeb3>] elevator_init+0xd3/0x140
> [ 157.970029] [<ffffffff81995ca2>] blk_init_allocated_queue+0xa2/0xd0
> [ 157.970029] [<ffffffff81995d0c>] blk_init_queue_node+0x3c/0x70
> [ 157.970029] [<ffffffff81995d4e>] blk_init_queue+0xe/0x10
> [ 157.970029] [<ffffffff8222a99f>] add_mtd_blktrans_dev+0x28f/0x410
> [ 157.970029] [<ffffffff8222b6d1>] mtdblock_add_mtd+0x81/0xa0
> [ 157.970029] [<ffffffff82229ea1>] blktrans_notify_add+0x31/0x50
> [ 157.970029] [<ffffffff82224047>] add_mtd_device+0x237/0x2e0
> [ 157.970029] [<ffffffff8222418c>] mtd_device_parse_register+0x9c/0xc0
> [ 157.970029] [<ffffffff8226ac04>] mtdram_init_device+0x114/0x120
> [ 157.970029] [<ffffffff85662443>] init_mtdram+0x81/0xfa
> [ 157.970029] [<ffffffff85600c9f>] do_one_initcall+0x7a/0x135
> [ 157.970029] [<ffffffff85600eb7>] kernel_init+0x15d/0x1e1
> [ 157.970029] [<ffffffff83762504>] kernel_thread_helper+0x4/0x10
> [ 157.970029] }
> [ 157.970029] ... key at: [<ffffffff865d3fac>] __key.29440+0x0/0x8
> [ 157.970029] ... acquired at:
> [ 157.970029] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
> [ 157.970029] [<ffffffff8375f6cc>] _raw_spin_lock_irqsave+0x7c/0xc0
> [ 157.970029] [<ffffffff812095be>] test_clear_page_writeback+0x6e/0x1b0
> [ 157.970029] [<ffffffff811fbdc4>] end_page_writeback+0x24/0x50
> [ 157.970029] [<ffffffff812a4372>] end_buffer_async_write+0x222/0x2f0
> [ 157.970029] [<ffffffff812a36cd>] end_bio_bh_io_sync+0x3d/0x50
> [ 157.970029] [<ffffffff812a8dfd>] bio_endio+0x2d/0x30
> [ 157.970029] [<ffffffff819921f5>] req_bio_endio.isra.36+0xb5/0xd0
> [ 157.970029] [<ffffffff819976ac>] blk_update_request+0x33c/0x600
> [ 157.970029] [<ffffffff81997992>] blk_update_bidi_request+0x22/0x90
> [ 157.970029] [<ffffffff81997abb>] __blk_end_bidi_request+0x1b/0x40
> [ 157.970029] [<ffffffff81997bcb>] __blk_end_request+0xb/0x10
> [ 157.970029] [<ffffffff81997fbd>] __blk_end_request_cur+0x3d/0x40
> [ 157.970029] [<ffffffff8222a234>] mtd_blktrans_thread+0x2c4/0x340
> [ 157.970029] [<ffffffff81135e13>] kthread+0xe3/0xf0
> [ 157.970029] [<ffffffff83762504>] kernel_thread_helper+0x4/0x10
> [ 157.970029]
> [ 157.970029] -> (&(&mapping->tree_lock)->rlock){+.+...} ops: 63737 {
> [ 157.970029] HARDIRQ-ON-W at:
> [ 157.970029] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
> [ 157.970029] [<ffffffff8117a567>] trace_hardirqs_on_caller+0x1f7/0x230
> [ 157.970029] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
> [ 157.970029] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
> [ 157.970029] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
> [ 157.970029] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
> [ 157.970029] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
> [ 157.970029] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
> [ 157.970029] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
> [ 157.970029] [<ffffffff81270468>] do_sync_write+0x98/0xf0
> [ 157.970029] [<ffffffff81270570>] vfs_write+0xb0/0x180
> [ 157.970029] [<ffffffff81270718>] sys_write+0x48/0x90
> [ 157.970029] [<ffffffff83761368>] tracesys+0xe1/0xe6
> [ 157.970029] SOFTIRQ-ON-W at:
> [ 157.970029] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
> [ 157.970029] [<ffffffff8117a4d5>] trace_hardirqs_on_caller+0x165/0x230
> [ 157.970029] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
> [ 157.970029] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
> [ 157.970029] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
> [ 157.970029] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
> [ 157.970029] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
> [ 157.970029] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
> [ 157.970029] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
> [ 157.970029] [<ffffffff81270468>] do_sync_write+0x98/0xf0
> [ 157.970029] [<ffffffff81270570>] vfs_write+0xb0/0x180
> [ 157.970029] [<ffffffff81270718>] sys_write+0x48/0x90
> [ 157.970029] [<ffffffff83761368>] tracesys+0xe1/0xe6
> [ 157.970029] INITIAL USE at:
> [ 157.970029] [<ffffffff8117c07f>] __lock_acquire+0x9cf/0x1bd0
> [ 157.970029] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
> [ 157.970029] [<ffffffff8375f767>] _raw_spin_lock_irq+0x57/0x90
> [ 157.970029] [<ffffffff8128c06c>] clear_inode+0x2c/0x90
> [ 157.970029] [<ffffffff81219629>] shmem_evict_inode+0x129/0x140
> [ 157.970029] [<ffffffff8128c179>] evict+0xa9/0x170
> [ 157.970029] [<ffffffff8128d04f>] iput+0x1cf/0x1f0
> [ 157.970029] [<ffffffff81289da0>] d_delete+0x150/0x1b0
> [ 157.970029] [<ffffffff812804c1>] vfs_unlink+0xe1/0x120
> [ 157.970029] [<ffffffff81e08814>] handle_remove+0x244/0x270
> [ 157.970029] [<ffffffff81e08b65>] devtmpfsd+0x125/0x170
> [ 157.970029] [<ffffffff81135e13>] kthread+0xe3/0xf0
> [ 157.970029] [<ffffffff83762504>] kernel_thread_helper+0x4/0x10
> [ 157.970029] }
> [ 157.970029] ... key at: [<ffffffff86226a60>] __key.30203+0x0/0x8
> [ 157.970029] ... acquired at:
> [ 157.970029] [<ffffffff811796be>] check_usage_backwards+0xce/0xe0
> [ 157.970029] [<ffffffff8117a0ad>] mark_lock+0x15d/0x2f0
> [ 157.970029] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
> [ 157.970029] [<ffffffff8117a4d5>] trace_hardirqs_on_caller+0x165/0x230
> [ 157.970029] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
> [ 157.970029] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
> [ 157.970029] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
> [ 157.970029] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
> [ 157.970029] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
> [ 157.970029] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
> [ 157.970029] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
> [ 157.970029] [<ffffffff81270468>] do_sync_write+0x98/0xf0
> [ 157.970029] [<ffffffff81270570>] vfs_write+0xb0/0x180
> [ 157.970029] [<ffffffff81270718>] sys_write+0x48/0x90
> [ 157.970029] [<ffffffff83761368>] tracesys+0xe1/0xe6
> [ 157.970029]
> [ 157.970029]
> [ 157.970029] stack backtrace:
> [ 157.970029] Pid: 6642, comm: trinity-child38 Tainted: G W
> 3.6.0-rc5-next-20120914-sasha-00001-g802bf6c-dirty #340
> [ 157.970029] Call Trace:
> [ 157.970029] [<ffffffff811794e1>] print_irq_inversion_bug+0x201/0x220
> [ 157.970029] [<ffffffff811796be>] check_usage_backwards+0xce/0xe0
> [ 157.970029] [<ffffffff811795f0>] ? check_usage_forwards+0xf0/0xf0
> [ 157.970029] [<ffffffff8117a0ad>] mark_lock+0x15d/0x2f0
> [ 157.970029] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
> [ 157.970029] [<ffffffff81177a9e>] ? put_lock_stats.isra.16+0xe/0x40
> [ 157.970029] [<ffffffff8375f95b>] ? _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8117a4d5>] trace_hardirqs_on_caller+0x165/0x230
> [ 157.970029] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
> [ 157.970029] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
> [ 157.970029] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
> [ 157.970029] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
> [ 157.970029] [<ffffffff8120951c>] ? do_writepages+0x1c/0x50
> [ 157.970029] [<ffffffff811fb4c9>] ? __filemap_fdatawrite_range+0x49/0x50
> [ 157.970029] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
> [ 157.970029] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
> [ 157.970029] [<ffffffff81177a12>] ? get_lock_stats+0x22/0x70
> [ 157.970029] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
> [ 157.970029] [<ffffffff8111b603>] ? del_timer+0x63/0x80
> [ 157.970029] [<ffffffff81270468>] do_sync_write+0x98/0xf0
> [ 157.970029] [<ffffffff81270570>] vfs_write+0xb0/0x180
> [ 157.970029] [<ffffffff81270718>] sys_write+0x48/0x90
> [ 157.970029] [<ffffffff83761368>] tracesys+0xe1/0xe6
>
Just got another related warning:
[ 197.827054] =================================
[ 197.828667] [ INFO: inconsistent lock state ]
[ 197.830035] 3.6.0-rc5-next-20120914-sasha-00001-g802bf6c-dirty #340 Tainted: G W
[ 197.830035] ---------------------------------
[ 197.830035] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[ 197.830035] trinity-child18/8192 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 197.830035] (&(&mapping->tree_lock)->rlock){+.?...}, at: [<ffffffff8120cafc>]
invalidate_inode_pages2_range+0x20c/0x3c0
[ 197.830035] {IN-SOFTIRQ-W} state was registered at:
[ 197.830035] [<ffffffff8117bf2a>] __lock_acquire+0x87a/0x1bd0
[ 197.830035] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
[ 197.830035] [<ffffffff8375f6cc>] _raw_spin_lock_irqsave+0x7c/0xc0
[ 197.830035] [<ffffffff812095be>] test_clear_page_writeback+0x6e/0x1b0
[ 197.830035] [<ffffffff811fbdc4>] end_page_writeback+0x24/0x50
[ 197.830035] [<ffffffff812a4372>] end_buffer_async_write+0x222/0x2f0
[ 197.830035] [<ffffffff812a36cd>] end_bio_bh_io_sync+0x3d/0x50
[ 197.830035] [<ffffffff812a8dfd>] bio_endio+0x2d/0x30
[ 197.830035] [<ffffffff819921f5>] req_bio_endio.isra.36+0xb5/0xd0
[ 197.830035] [<ffffffff819976ac>] blk_update_request+0x33c/0x600
[ 197.830035] [<ffffffff81997992>] blk_update_bidi_request+0x22/0x90
[ 197.830035] [<ffffffff81997a27>] blk_end_bidi_request+0x27/0x70
[ 197.830035] [<ffffffff81997aeb>] blk_end_request+0xb/0x10
[ 197.830035] [<ffffffff81ede493>] scsi_io_completion+0x263/0x6b0
[ 197.830035] [<ffffffff81ed7168>] scsi_finish_command+0x118/0x130
[ 197.830035] [<ffffffff81ede145>] scsi_softirq_done+0x135/0x150
[ 197.830035] [<ffffffff8199dd60>] blk_done_softirq+0xb0/0xd0
[ 197.830035] [<ffffffff81110b27>] __do_softirq+0x1c7/0x440
[ 197.830035] [<ffffffff8376256c>] call_softirq+0x1c/0x30
[ 197.830035] [<ffffffff8106f51d>] do_softirq+0x6d/0x100
[ 197.830035] [<ffffffff81110f1a>] irq_exit+0x5a/0xd0
[ 197.830035] [<ffffffff8109674a>] smp_apic_timer_interrupt+0x8a/0xa0
[ 197.830035] [<ffffffff83761e6f>] apic_timer_interrupt+0x6f/0x80
[ 197.830035] [<ffffffff810775b5>] default_idle+0x235/0x5b0
[ 197.830035] [<ffffffff810785e8>] cpu_idle+0x138/0x160
[ 197.830035] [<ffffffff836fbed7>] start_secondary+0x26e/0x276
[ 197.830035] irq event stamp: 178348
[ 197.830035] hardirqs last enabled at (178347): [<ffffffff8375f8dd>]
_raw_spin_unlock_irqrestore+0x5d/0xb0
[ 197.830035] hardirqs last disabled at (178348): [<ffffffff8375f73a>]
_raw_spin_lock_irq+0x2a/0x90
[ 197.830035] softirqs last enabled at (168698): [<ffffffff81110cd2>]
__do_softirq+0x372/0x440
[ 197.830035] softirqs last disabled at (168687): [<ffffffff8376256c>]
call_softirq+0x1c/0x30
[ 197.830035]
[ 197.830035] other info that might help us debug this:
[ 197.830035] Possible unsafe locking scenario:
[ 197.830035]
[ 197.830035] CPU0
[ 197.830035] ----
[ 197.830035] lock(&(&mapping->tree_lock)->rlock);
[ 197.830035] <Interrupt>
[ 197.830035] lock(&(&mapping->tree_lock)->rlock);
[ 197.830035]
[ 197.830035] *** DEADLOCK ***
[ 197.830035]
[ 197.830035] 1 lock held by trinity-child18/8192:
[ 197.830035] #0: (&(&mapping->tree_lock)->rlock){+.?...}, at:
[<ffffffff8120cafc>] invalidate_inode_pages2_range+0x20c/0x3c0
[ 197.830035]
[ 197.830035] stack backtrace:
[ 197.830035] Pid: 8192, comm: trinity-child18 Tainted: G W
3.6.0-rc5-next-20120914-sasha-00001-g802bf6c-dirty #340
[ 197.830035] Call Trace:
[ 197.830035] [<ffffffff8370a28a>] print_usage_bug+0x1f7/0x208
[ 197.830035] [<ffffffff8107d9ba>] ? save_stack_trace+0x2a/0x50
[ 197.830035] [<ffffffff811795f0>] ? check_usage_forwards+0xf0/0xf0
[ 197.830035] [<ffffffff8117a0c6>] mark_lock+0x176/0x2f0
[ 197.830035] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
[ 197.830035] [<ffffffff81177a9e>] ? put_lock_stats.isra.16+0xe/0x40
[ 197.830035] [<ffffffff8375f95b>] ? _raw_spin_unlock_irq+0x2b/0x80
[ 197.830035] [<ffffffff8117a4d5>] trace_hardirqs_on_caller+0x165/0x230
[ 197.830035] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
[ 197.830035] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
[ 197.830035] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
[ 197.830035] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
[ 197.830035] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
[ 197.830035] [<ffffffff8120951c>] ? do_writepages+0x1c/0x50
[ 197.830035] [<ffffffff811fb4c9>] ? __filemap_fdatawrite_range+0x49/0x50
[ 197.830035] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
[ 197.830035] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
[ 197.830035] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
[ 197.830035] [<ffffffff812aab70>] ? block_llseek+0xc0/0xc0
[ 197.830035] [<ffffffff8127097c>] do_sync_readv_writev+0x8c/0xe0
[ 197.830035] [<ffffffff81270c79>] do_readv_writev+0xd9/0x1e0
[ 197.830035] [<ffffffff811c63d5>] ? rcu_user_exit+0xa5/0xd0
[ 197.830035] [<ffffffff81270e1a>] vfs_writev+0x3a/0x60
[ 197.830035] [<ffffffff81270f38>] sys_writev+0x48/0xb0
[ 197.830035] [<ffffffff83761368>] tracesys+0xe1/0xe6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Sasha Levin <levinsasha928@gmail.com>
To: axboe@kernel.dk, Tejun Heo <tj@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Dave Jones <davej@redhat.com>
Subject: Re: blk, mm: lockdep irq lock inversion in linux-next
Date: Sat, 15 Sep 2012 16:02:10 +0200 [thread overview]
Message-ID: <50548A62.5000005@gmail.com> (raw)
In-Reply-To: <5054878F.1030908@gmail.com>
On 09/15/2012 03:50 PM, Sasha Levin wrote:
> Hi all,
>
> While fuzzing with trinity within a KVM tools guest on a linux-next kernel, I
> got the lockdep warning at the bottom of this mail.
>
> I've tried figuring out where it was introduced, but haven't found any sign that
> any of the code in that area changed recently, so I'm probably missing something...
>
>
> [ 157.966399] =========================================================
> [ 157.968523] [ INFO: possible irq lock inversion dependency detected ]
> [ 157.970029] 3.6.0-rc5-next-20120914-sasha-00001-g802bf6c-dirty #340 Tainted: G W
> [ 157.970029] ---------------------------------------------------------
> [ 157.970029] trinity-child38/6642 just changed the state of lock:
> [ 157.970029] (&(&mapping->tree_lock)->rlock){+.+...}, at: [<ffffffff8120cafc>]
> invalidate_inode_pages2_range+0x20c/0x3c0
> [ 157.970029] but this lock was taken by another, SOFTIRQ-safe lock in the past:
> [ 157.970029] (&(&new->queue_lock)->rlock){..-...}
>
> and interrupts could create inverse lock ordering between them.
>
> [ 157.970029]
> [ 157.970029] other info that might help us debug this:
> [ 157.970029] Possible interrupt unsafe locking scenario:
> [ 157.970029]
> [ 157.970029] CPU0 CPU1
> [ 157.970029] ---- ----
> [ 157.970029] lock(&(&mapping->tree_lock)->rlock);
> [ 157.970029] local_irq_disable();
> [ 157.970029] lock(&(&new->queue_lock)->rlock);
> [ 157.970029] lock(&(&mapping->tree_lock)->rlock);
> [ 157.970029] <Interrupt>
> [ 157.970029] lock(&(&new->queue_lock)->rlock);
> [ 157.970029]
> [ 157.970029] *** DEADLOCK ***
> [ 157.970029]
> [ 157.970029] 1 lock held by trinity-child38/6642:
> [ 157.970029] #0: (&(&mapping->tree_lock)->rlock){+.+...}, at:
> [<ffffffff8120cafc>] invalidate_inode_pages2_range+0x20c/0x3c0
> [ 157.970029]
> [ 157.970029] the shortest dependencies between 2nd lock and 1st lock:
> [ 157.970029] -> (&(&new->queue_lock)->rlock){..-...} ops: 4790 {
> [ 157.970029] IN-SOFTIRQ-W at:
> [ 157.970029] [<ffffffff8117bf2a>] __lock_acquire+0x87a/0x1bd0
> [ 157.970029] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
> [ 157.970029] [<ffffffff8375f6cc>] _raw_spin_lock_irqsave+0x7c/0xc0
> [ 157.970029] [<ffffffff819b7239>] cfq_idle_slice_timer+0x19/0xd0
> [ 157.970029] [<ffffffff81119f66>] call_timer_fn+0x166/0x380
> [ 157.970029] [<ffffffff8111a46c>] run_timer_softirq+0x2ec/0x380
> [ 157.970029] [<ffffffff81110b27>] __do_softirq+0x1c7/0x440
> [ 157.970029] [<ffffffff8376256c>] call_softirq+0x1c/0x30
> [ 157.970029] [<ffffffff8106f51d>] do_softirq+0x6d/0x100
> [ 157.970029] [<ffffffff81110f1a>] irq_exit+0x5a/0xd0
> [ 157.970029] [<ffffffff8109674a>] smp_apic_timer_interrupt+0x8a/0xa0
> [ 157.970029] [<ffffffff83761e6f>] apic_timer_interrupt+0x6f/0x80
> [ 157.970029] [<ffffffff810775b5>] default_idle+0x235/0x5b0
> [ 157.970029] [<ffffffff810785e8>] cpu_idle+0x138/0x160
> [ 157.970029] [<ffffffff836fbed7>] start_secondary+0x26e/0x276
> [ 157.970029] INITIAL USE at:
> [ 157.970029] [<ffffffff8117c07f>] __lock_acquire+0x9cf/0x1bd0
> [ 157.970029] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
> [ 157.970029] [<ffffffff8375f767>] _raw_spin_lock_irq+0x57/0x90
> [ 157.970029] [<ffffffff819954e6>] blk_queue_bypass_start+0x16/0xa0
> [ 157.970029] [<ffffffff819af017>] blkcg_activate_policy+0x67/0x370
> [ 157.970029] [<ffffffff819b3d09>] cfq_init_queue+0x79/0x380
> [ 157.970029] [<ffffffff8198eeb3>] elevator_init+0xd3/0x140
> [ 157.970029] [<ffffffff81995ca2>] blk_init_allocated_queue+0xa2/0xd0
> [ 157.970029] [<ffffffff81995d0c>] blk_init_queue_node+0x3c/0x70
> [ 157.970029] [<ffffffff81995d4e>] blk_init_queue+0xe/0x10
> [ 157.970029] [<ffffffff8222a99f>] add_mtd_blktrans_dev+0x28f/0x410
> [ 157.970029] [<ffffffff8222b6d1>] mtdblock_add_mtd+0x81/0xa0
> [ 157.970029] [<ffffffff82229ea1>] blktrans_notify_add+0x31/0x50
> [ 157.970029] [<ffffffff82224047>] add_mtd_device+0x237/0x2e0
> [ 157.970029] [<ffffffff8222418c>] mtd_device_parse_register+0x9c/0xc0
> [ 157.970029] [<ffffffff8226ac04>] mtdram_init_device+0x114/0x120
> [ 157.970029] [<ffffffff85662443>] init_mtdram+0x81/0xfa
> [ 157.970029] [<ffffffff85600c9f>] do_one_initcall+0x7a/0x135
> [ 157.970029] [<ffffffff85600eb7>] kernel_init+0x15d/0x1e1
> [ 157.970029] [<ffffffff83762504>] kernel_thread_helper+0x4/0x10
> [ 157.970029] }
> [ 157.970029] ... key at: [<ffffffff865d3fac>] __key.29440+0x0/0x8
> [ 157.970029] ... acquired at:
> [ 157.970029] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
> [ 157.970029] [<ffffffff8375f6cc>] _raw_spin_lock_irqsave+0x7c/0xc0
> [ 157.970029] [<ffffffff812095be>] test_clear_page_writeback+0x6e/0x1b0
> [ 157.970029] [<ffffffff811fbdc4>] end_page_writeback+0x24/0x50
> [ 157.970029] [<ffffffff812a4372>] end_buffer_async_write+0x222/0x2f0
> [ 157.970029] [<ffffffff812a36cd>] end_bio_bh_io_sync+0x3d/0x50
> [ 157.970029] [<ffffffff812a8dfd>] bio_endio+0x2d/0x30
> [ 157.970029] [<ffffffff819921f5>] req_bio_endio.isra.36+0xb5/0xd0
> [ 157.970029] [<ffffffff819976ac>] blk_update_request+0x33c/0x600
> [ 157.970029] [<ffffffff81997992>] blk_update_bidi_request+0x22/0x90
> [ 157.970029] [<ffffffff81997abb>] __blk_end_bidi_request+0x1b/0x40
> [ 157.970029] [<ffffffff81997bcb>] __blk_end_request+0xb/0x10
> [ 157.970029] [<ffffffff81997fbd>] __blk_end_request_cur+0x3d/0x40
> [ 157.970029] [<ffffffff8222a234>] mtd_blktrans_thread+0x2c4/0x340
> [ 157.970029] [<ffffffff81135e13>] kthread+0xe3/0xf0
> [ 157.970029] [<ffffffff83762504>] kernel_thread_helper+0x4/0x10
> [ 157.970029]
> [ 157.970029] -> (&(&mapping->tree_lock)->rlock){+.+...} ops: 63737 {
> [ 157.970029] HARDIRQ-ON-W at:
> [ 157.970029] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
> [ 157.970029] [<ffffffff8117a567>] trace_hardirqs_on_caller+0x1f7/0x230
> [ 157.970029] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
> [ 157.970029] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
> [ 157.970029] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
> [ 157.970029] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
> [ 157.970029] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
> [ 157.970029] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
> [ 157.970029] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
> [ 157.970029] [<ffffffff81270468>] do_sync_write+0x98/0xf0
> [ 157.970029] [<ffffffff81270570>] vfs_write+0xb0/0x180
> [ 157.970029] [<ffffffff81270718>] sys_write+0x48/0x90
> [ 157.970029] [<ffffffff83761368>] tracesys+0xe1/0xe6
> [ 157.970029] SOFTIRQ-ON-W at:
> [ 157.970029] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
> [ 157.970029] [<ffffffff8117a4d5>] trace_hardirqs_on_caller+0x165/0x230
> [ 157.970029] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
> [ 157.970029] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
> [ 157.970029] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
> [ 157.970029] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
> [ 157.970029] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
> [ 157.970029] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
> [ 157.970029] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
> [ 157.970029] [<ffffffff81270468>] do_sync_write+0x98/0xf0
> [ 157.970029] [<ffffffff81270570>] vfs_write+0xb0/0x180
> [ 157.970029] [<ffffffff81270718>] sys_write+0x48/0x90
> [ 157.970029] [<ffffffff83761368>] tracesys+0xe1/0xe6
> [ 157.970029] INITIAL USE at:
> [ 157.970029] [<ffffffff8117c07f>] __lock_acquire+0x9cf/0x1bd0
> [ 157.970029] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
> [ 157.970029] [<ffffffff8375f767>] _raw_spin_lock_irq+0x57/0x90
> [ 157.970029] [<ffffffff8128c06c>] clear_inode+0x2c/0x90
> [ 157.970029] [<ffffffff81219629>] shmem_evict_inode+0x129/0x140
> [ 157.970029] [<ffffffff8128c179>] evict+0xa9/0x170
> [ 157.970029] [<ffffffff8128d04f>] iput+0x1cf/0x1f0
> [ 157.970029] [<ffffffff81289da0>] d_delete+0x150/0x1b0
> [ 157.970029] [<ffffffff812804c1>] vfs_unlink+0xe1/0x120
> [ 157.970029] [<ffffffff81e08814>] handle_remove+0x244/0x270
> [ 157.970029] [<ffffffff81e08b65>] devtmpfsd+0x125/0x170
> [ 157.970029] [<ffffffff81135e13>] kthread+0xe3/0xf0
> [ 157.970029] [<ffffffff83762504>] kernel_thread_helper+0x4/0x10
> [ 157.970029] }
> [ 157.970029] ... key at: [<ffffffff86226a60>] __key.30203+0x0/0x8
> [ 157.970029] ... acquired at:
> [ 157.970029] [<ffffffff811796be>] check_usage_backwards+0xce/0xe0
> [ 157.970029] [<ffffffff8117a0ad>] mark_lock+0x15d/0x2f0
> [ 157.970029] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
> [ 157.970029] [<ffffffff8117a4d5>] trace_hardirqs_on_caller+0x165/0x230
> [ 157.970029] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
> [ 157.970029] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
> [ 157.970029] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
> [ 157.970029] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
> [ 157.970029] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
> [ 157.970029] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
> [ 157.970029] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
> [ 157.970029] [<ffffffff81270468>] do_sync_write+0x98/0xf0
> [ 157.970029] [<ffffffff81270570>] vfs_write+0xb0/0x180
> [ 157.970029] [<ffffffff81270718>] sys_write+0x48/0x90
> [ 157.970029] [<ffffffff83761368>] tracesys+0xe1/0xe6
> [ 157.970029]
> [ 157.970029]
> [ 157.970029] stack backtrace:
> [ 157.970029] Pid: 6642, comm: trinity-child38 Tainted: G W
> 3.6.0-rc5-next-20120914-sasha-00001-g802bf6c-dirty #340
> [ 157.970029] Call Trace:
> [ 157.970029] [<ffffffff811794e1>] print_irq_inversion_bug+0x201/0x220
> [ 157.970029] [<ffffffff811796be>] check_usage_backwards+0xce/0xe0
> [ 157.970029] [<ffffffff811795f0>] ? check_usage_forwards+0xf0/0xf0
> [ 157.970029] [<ffffffff8117a0ad>] mark_lock+0x15d/0x2f0
> [ 157.970029] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
> [ 157.970029] [<ffffffff81177a9e>] ? put_lock_stats.isra.16+0xe/0x40
> [ 157.970029] [<ffffffff8375f95b>] ? _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8117a4d5>] trace_hardirqs_on_caller+0x165/0x230
> [ 157.970029] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
> [ 157.970029] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
> [ 157.970029] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
> [ 157.970029] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
> [ 157.970029] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
> [ 157.970029] [<ffffffff8120951c>] ? do_writepages+0x1c/0x50
> [ 157.970029] [<ffffffff811fb4c9>] ? __filemap_fdatawrite_range+0x49/0x50
> [ 157.970029] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
> [ 157.970029] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
> [ 157.970029] [<ffffffff81177a12>] ? get_lock_stats+0x22/0x70
> [ 157.970029] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
> [ 157.970029] [<ffffffff8111b603>] ? del_timer+0x63/0x80
> [ 157.970029] [<ffffffff81270468>] do_sync_write+0x98/0xf0
> [ 157.970029] [<ffffffff81270570>] vfs_write+0xb0/0x180
> [ 157.970029] [<ffffffff81270718>] sys_write+0x48/0x90
> [ 157.970029] [<ffffffff83761368>] tracesys+0xe1/0xe6
>
Just got another related warning:
[ 197.827054] =================================
[ 197.828667] [ INFO: inconsistent lock state ]
[ 197.830035] 3.6.0-rc5-next-20120914-sasha-00001-g802bf6c-dirty #340 Tainted: G W
[ 197.830035] ---------------------------------
[ 197.830035] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[ 197.830035] trinity-child18/8192 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 197.830035] (&(&mapping->tree_lock)->rlock){+.?...}, at: [<ffffffff8120cafc>]
invalidate_inode_pages2_range+0x20c/0x3c0
[ 197.830035] {IN-SOFTIRQ-W} state was registered at:
[ 197.830035] [<ffffffff8117bf2a>] __lock_acquire+0x87a/0x1bd0
[ 197.830035] [<ffffffff8117f87a>] lock_acquire+0x1aa/0x240
[ 197.830035] [<ffffffff8375f6cc>] _raw_spin_lock_irqsave+0x7c/0xc0
[ 197.830035] [<ffffffff812095be>] test_clear_page_writeback+0x6e/0x1b0
[ 197.830035] [<ffffffff811fbdc4>] end_page_writeback+0x24/0x50
[ 197.830035] [<ffffffff812a4372>] end_buffer_async_write+0x222/0x2f0
[ 197.830035] [<ffffffff812a36cd>] end_bio_bh_io_sync+0x3d/0x50
[ 197.830035] [<ffffffff812a8dfd>] bio_endio+0x2d/0x30
[ 197.830035] [<ffffffff819921f5>] req_bio_endio.isra.36+0xb5/0xd0
[ 197.830035] [<ffffffff819976ac>] blk_update_request+0x33c/0x600
[ 197.830035] [<ffffffff81997992>] blk_update_bidi_request+0x22/0x90
[ 197.830035] [<ffffffff81997a27>] blk_end_bidi_request+0x27/0x70
[ 197.830035] [<ffffffff81997aeb>] blk_end_request+0xb/0x10
[ 197.830035] [<ffffffff81ede493>] scsi_io_completion+0x263/0x6b0
[ 197.830035] [<ffffffff81ed7168>] scsi_finish_command+0x118/0x130
[ 197.830035] [<ffffffff81ede145>] scsi_softirq_done+0x135/0x150
[ 197.830035] [<ffffffff8199dd60>] blk_done_softirq+0xb0/0xd0
[ 197.830035] [<ffffffff81110b27>] __do_softirq+0x1c7/0x440
[ 197.830035] [<ffffffff8376256c>] call_softirq+0x1c/0x30
[ 197.830035] [<ffffffff8106f51d>] do_softirq+0x6d/0x100
[ 197.830035] [<ffffffff81110f1a>] irq_exit+0x5a/0xd0
[ 197.830035] [<ffffffff8109674a>] smp_apic_timer_interrupt+0x8a/0xa0
[ 197.830035] [<ffffffff83761e6f>] apic_timer_interrupt+0x6f/0x80
[ 197.830035] [<ffffffff810775b5>] default_idle+0x235/0x5b0
[ 197.830035] [<ffffffff810785e8>] cpu_idle+0x138/0x160
[ 197.830035] [<ffffffff836fbed7>] start_secondary+0x26e/0x276
[ 197.830035] irq event stamp: 178348
[ 197.830035] hardirqs last enabled at (178347): [<ffffffff8375f8dd>]
_raw_spin_unlock_irqrestore+0x5d/0xb0
[ 197.830035] hardirqs last disabled at (178348): [<ffffffff8375f73a>]
_raw_spin_lock_irq+0x2a/0x90
[ 197.830035] softirqs last enabled at (168698): [<ffffffff81110cd2>]
__do_softirq+0x372/0x440
[ 197.830035] softirqs last disabled at (168687): [<ffffffff8376256c>]
call_softirq+0x1c/0x30
[ 197.830035]
[ 197.830035] other info that might help us debug this:
[ 197.830035] Possible unsafe locking scenario:
[ 197.830035]
[ 197.830035] CPU0
[ 197.830035] ----
[ 197.830035] lock(&(&mapping->tree_lock)->rlock);
[ 197.830035] <Interrupt>
[ 197.830035] lock(&(&mapping->tree_lock)->rlock);
[ 197.830035]
[ 197.830035] *** DEADLOCK ***
[ 197.830035]
[ 197.830035] 1 lock held by trinity-child18/8192:
[ 197.830035] #0: (&(&mapping->tree_lock)->rlock){+.?...}, at:
[<ffffffff8120cafc>] invalidate_inode_pages2_range+0x20c/0x3c0
[ 197.830035]
[ 197.830035] stack backtrace:
[ 197.830035] Pid: 8192, comm: trinity-child18 Tainted: G W
3.6.0-rc5-next-20120914-sasha-00001-g802bf6c-dirty #340
[ 197.830035] Call Trace:
[ 197.830035] [<ffffffff8370a28a>] print_usage_bug+0x1f7/0x208
[ 197.830035] [<ffffffff8107d9ba>] ? save_stack_trace+0x2a/0x50
[ 197.830035] [<ffffffff811795f0>] ? check_usage_forwards+0xf0/0xf0
[ 197.830035] [<ffffffff8117a0c6>] mark_lock+0x176/0x2f0
[ 197.830035] [<ffffffff8117a353>] mark_held_locks+0x113/0x130
[ 197.830035] [<ffffffff81177a9e>] ? put_lock_stats.isra.16+0xe/0x40
[ 197.830035] [<ffffffff8375f95b>] ? _raw_spin_unlock_irq+0x2b/0x80
[ 197.830035] [<ffffffff8117a4d5>] trace_hardirqs_on_caller+0x165/0x230
[ 197.830035] [<ffffffff8117a5ad>] trace_hardirqs_on+0xd/0x10
[ 197.830035] [<ffffffff8375f95b>] _raw_spin_unlock_irq+0x2b/0x80
[ 197.830035] [<ffffffff8121076d>] isolate_lru_page+0x15d/0x180
[ 197.830035] [<ffffffff8122d39a>] __clear_page_mlock+0x3a/0x70
[ 197.830035] [<ffffffff8120cb35>] invalidate_inode_pages2_range+0x245/0x3c0
[ 197.830035] [<ffffffff8120951c>] ? do_writepages+0x1c/0x50
[ 197.830035] [<ffffffff811fb4c9>] ? __filemap_fdatawrite_range+0x49/0x50
[ 197.830035] [<ffffffff811fe1f7>] generic_file_direct_write+0xc7/0x180
[ 197.830035] [<ffffffff811fe8c9>] __generic_file_aio_write+0x249/0x3a0
[ 197.830035] [<ffffffff812aabc1>] blkdev_aio_write+0x51/0xb0
[ 197.830035] [<ffffffff812aab70>] ? block_llseek+0xc0/0xc0
[ 197.830035] [<ffffffff8127097c>] do_sync_readv_writev+0x8c/0xe0
[ 197.830035] [<ffffffff81270c79>] do_readv_writev+0xd9/0x1e0
[ 197.830035] [<ffffffff811c63d5>] ? rcu_user_exit+0xa5/0xd0
[ 197.830035] [<ffffffff81270e1a>] vfs_writev+0x3a/0x60
[ 197.830035] [<ffffffff81270f38>] sys_writev+0x48/0xb0
[ 197.830035] [<ffffffff83761368>] tracesys+0xe1/0xe6
next prev parent reply other threads:[~2012-09-15 14:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-15 13:50 blk, mm: lockdep irq lock inversion in linux-next Sasha Levin
2012-09-15 13:50 ` Sasha Levin
2012-09-15 14:02 ` Sasha Levin [this message]
2012-09-15 14:02 ` Sasha Levin
2012-09-17 23:22 ` Andrew Morton
2012-09-17 23:22 ` Andrew Morton
2012-09-17 23:58 ` Hugh Dickins
2012-09-17 23:58 ` Hugh Dickins
2012-09-19 3:45 ` Hugh Dickins
2012-09-19 3:45 ` Hugh Dickins
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=50548A62.5000005@gmail.com \
--to=levinsasha928@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=axboe@kernel.dk \
--cc=davej@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.