On Tue, Jan 08, 2013 at 04:31:30PM +0900, Jun'ichi Nomura wrote: > With 749fefe677 in v3.7 ("block: lift the initial queue bypass mode > on blk_register_queue() instead of blk_init_allocated_queue()"), > the following warning appears when multipath is used with CONFIG_PREEMPT=y. > > This patch moves blk_queue_bypass_start() before radix_tree_preload() > to avoid the sleeping call while preemption is disabled. > > BUG: scheduling while atomic: multipath/2460/0x00000002 > 1 lock held by multipath/2460: > #0: (&md->type_lock){......}, at: [<ffffffffa019fb05>] dm_lock_md_type+0x17/0x19 [dm_mod] > Modules linked in: ... > Pid: 2460, comm: multipath Tainted: G W 3.7.0-rc2 #1 > Call Trace: > [<ffffffff810723ae>] __schedule_bug+0x6a/0x78 > [<ffffffff81428ba2>] __schedule+0xb4/0x5e0 > [<ffffffff814291e6>] schedule+0x64/0x66 > [<ffffffff8142773a>] schedule_timeout+0x39/0xf8 > [<ffffffff8108ad5f>] ? put_lock_stats+0xe/0x29 > [<ffffffff8108ae30>] ? lock_release_holdtime+0xb6/0xbb > [<ffffffff814289e3>] wait_for_common+0x9d/0xee > [<ffffffff8107526c>] ? try_to_wake_up+0x206/0x206 > [<ffffffff810c0eb8>] ? kfree_call_rcu+0x1c/0x1c > [<ffffffff81428aec>] wait_for_completion+0x1d/0x1f > [<ffffffff810611f9>] wait_rcu_gp+0x5d/0x7a > [<ffffffff81061216>] ? wait_rcu_gp+0x7a/0x7a > [<ffffffff8106fb18>] ? complete+0x21/0x53 > [<ffffffff810c0556>] synchronize_rcu+0x1e/0x20 > [<ffffffff811dd903>] blk_queue_bypass_start+0x5d/0x62 > [<ffffffff811ee109>] blkcg_activate_policy+0x73/0x270 > [<ffffffff81130521>] ? kmem_cache_alloc_node_trace+0xc7/0x108 > [<ffffffff811f04b3>] cfq_init_queue+0x80/0x28e > [<ffffffffa01a1600>] ? dm_blk_ioctl+0xa7/0xa7 [dm_mod] > [<ffffffff811d8c41>] elevator_init+0xe1/0x115 > [<ffffffff811e229f>] ? blk_queue_make_request+0x54/0x59 > [<ffffffff811dd743>] blk_init_allocated_queue+0x8c/0x9e > [<ffffffffa019ffcd>] dm_setup_md_queue+0x36/0xaa [dm_mod] > [<ffffffffa01a60e6>] table_load+0x1bd/0x2c8 [dm_mod] > [<ffffffffa01a7026>] ctl_ioctl+0x1d6/0x236 [dm_mod] > [<ffffffffa01a5f29>] ? table_clear+0xaa/0xaa [dm_mod] > [<ffffffffa01a7099>] dm_ctl_ioctl+0x13/0x17 [dm_mod] > [<ffffffff811479fc>] do_vfs_ioctl+0x3fb/0x441 > [<ffffffff811b643c>] ? file_has_perm+0x8a/0x99 > [<ffffffff81147aa0>] sys_ioctl+0x5e/0x82 > [<ffffffff812010be>] ? trace_hardirqs_on_thunk+0x3a/0x3f > [<ffffffff814310d9>] system_call_fastpath+0x16/0x1b > > Signed-off-by: Jun'ichi Nomura <j-nomura@xxxxxxxxxxxxx> > Acked-by: Vivek Goyal <vgoyal@xxxxxxxxxx> > Cc: Tejun Heo <tj@xxxxxxxxxx> > Cc: Jens Axboe <axboe@xxxxxxxxx> > Cc: Alasdair G Kergon <agk@xxxxxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> Thanks. -- tejun -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel