* Re: [PATCH] blkcg: fix "scheduling while atomic" in blk_queue_bypass_start
@ 2012-10-30 6:32 Staci Page
0 siblings, 0 replies; 3+ messages in thread
From: Staci Page @ 2012-10-30 6:32 UTC (permalink / raw)
To: device-mapper development
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Hello, I just got a minute to message back bc I am workin. I'll give ya my link on this site my pictures and some stuff. Just call or text message if you're interested. K gtg ttyl
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] blkcg: fix "scheduling while atomic" in blk_queue_bypass_start
2012-10-30 2:25 ` [PATCH] blkcg: fix "scheduling while atomic" in blk_queue_bypass_start Jun'ichi Nomura
@ 2012-10-30 13:21 ` Vivek Goyal
0 siblings, 0 replies; 3+ messages in thread
From: Vivek Goyal @ 2012-10-30 13:21 UTC (permalink / raw)
To: Jun'ichi Nomura
Cc: Peter Zijlstra, linux-kernel, device-mapper development,
Tejun Heo, Jens Axboe, Alasdair G Kergon, Paul E. McKenney
On Tue, Oct 30, 2012 at 11:25:47AM +0900, Jun'ichi Nomura wrote:
[..]
> 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@ce.jp.nec.com>
> Cc: Vivek Goyal <vgoyal@redhat.com>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Alasdair G Kergon <agk@redhat.com>
> ---
Thanks Junichi. This patch looks good to me.
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Vivek
> block/blk-cgroup.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index d0b7703..954f4be 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -791,10 +791,10 @@ int blkcg_activate_policy(struct request_queue *q,
> if (!blkg)
> return -ENOMEM;
>
> - preloaded = !radix_tree_preload(GFP_KERNEL);
> -
> blk_queue_bypass_start(q);
>
> + preloaded = !radix_tree_preload(GFP_KERNEL);
> +
> /* make sure the root blkg exists and count the existing blkgs */
> spin_lock_irq(q->queue_lock);
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] blkcg: fix "scheduling while atomic" in blk_queue_bypass_start
2012-10-29 17:13 ` Vivek Goyal
@ 2012-10-30 2:25 ` Jun'ichi Nomura
2012-10-30 13:21 ` Vivek Goyal
0 siblings, 1 reply; 3+ messages in thread
From: Jun'ichi Nomura @ 2012-10-30 2:25 UTC (permalink / raw)
To: Vivek Goyal
Cc: Peter Zijlstra, linux-kernel, device-mapper development,
Tejun Heo, Jens Axboe, Alasdair G Kergon, Paul E. McKenney
On 10/30/12 02:13, Vivek Goyal wrote:
> On Mon, Oct 29, 2012 at 05:45:15PM +0100, Peter Zijlstra wrote:
>> int radix_tree_preload(gfp_t gfp_mask)
>> {
>> struct radix_tree_preload *rtp;
>> struct radix_tree_node *node;
>> int ret = -ENOMEM;
>>
>> preempt_disable();
>>
>>
>> Seems obvious why it explodes..
>
> Oh right. Thanks Peter. So just calling blk_queue_bypass_start() before
> radix_tree_preload() should fix it. Junichi, can you please give it
> a try.
Thank you! It just works.
This is a revised patch.
With 749fefe677 ("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@ce.jp.nec.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alasdair G Kergon <agk@redhat.com>
---
block/blk-cgroup.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index d0b7703..954f4be 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -791,10 +791,10 @@ int blkcg_activate_policy(struct request_queue *q,
if (!blkg)
return -ENOMEM;
- preloaded = !radix_tree_preload(GFP_KERNEL);
-
blk_queue_bypass_start(q);
+ preloaded = !radix_tree_preload(GFP_KERNEL);
+
/* make sure the root blkg exists and count the existing blkgs */
spin_lock_irq(q->queue_lock);
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-10-30 13:22 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-10-30 6:32 [PATCH] blkcg: fix "scheduling while atomic" in blk_queue_bypass_start Staci Page
-- strict thread matches above, loose matches on Subject: below --
2012-10-25 9:41 [PATCH 2/2] dm: stay in blk_queue_bypass until queue becomes initialized Jun'ichi Nomura
2012-10-26 20:21 ` Vivek Goyal
2012-10-29 10:15 ` Jun'ichi Nomura
2012-10-29 16:38 ` Vivek Goyal
2012-10-29 16:45 ` Peter Zijlstra
2012-10-29 17:13 ` Vivek Goyal
2012-10-30 2:25 ` [PATCH] blkcg: fix "scheduling while atomic" in blk_queue_bypass_start Jun'ichi Nomura
2012-10-30 13:21 ` Vivek Goyal
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