Added missing idr_preload_end() call in worker_pool_assign_id().
Without it preemption stays disabled resulting in lots of "scheduling while
atomic" BUGs during boot.
[ 0.167848] BUG: scheduling while atomic: swapper/0/1/0x10000009
[ 0.167951] no locks held by swapper/0/1.
[ 0.168046] Modules linked in:
[ 0.168947] Pid: 1, comm: swapper/0 Not tainted 3.9.0-rc2-next-20130313+ #299
[ 0.169054] Call Trace:
[ 0.169152] [<c168369e>] __schedule_bug+0x59/0x6b
[ 0.169254] [<c168d0d8>] __schedule+0x858/0x8e0
[ 0.169355] [<c1066bbb>] __cond_resched+0x1b/0x30
[ 0.169457] [<c168d1d6>] _cond_resched+0x26/0x30
[ 0.169555] [<c168d20e>] wait_for_common+0x2e/0x120
[ 0.169659] [<c1068fc7>] ? try_to_wake_up+0x197/0x280
[ 0.169760] [<c168d317>] wait_for_completion+0x17/0x20
[ 0.169860] [<c105a2c6>] kthread_create_on_node+0x76/0xc0
[ 0.169963] [<c1052400>] ? rescuer_thread+0x220/0x220
[ 0.170064] [<c1090f72>] ? lockdep_init_map+0x92/0x4e0
[ 0.170164] [<c104fbc1>] create_worker+0xd1/0x1a0
[ 0.170261] [<c1052400>] ? rescuer_thread+0x220/0x220
[ 0.170367] [<c19d1fb9>] init_workqueues+0x12c/0x331
[ 0.170468] [<c19d1e8d>] ? ftrace_define_fields_workqueue_queue_work+0x115/0x115
[ 0.170620] [<c1001222>] do_one_initcall+0x112/0x160
[ 0.170723] [<c19c7ce6>] ? native_smp_prepare_cpus+0x39a/0x3fd
[ 0.170829] [<c19bca94>] kernel_init_freeable+0x83/0x1b8
[ 0.170931] [<c106503b>] ? finish_task_switch+0x3b/0x100
[ 0.171035] [<c1676970>] kernel_init+0x10/0xd0
[ 0.171133] [<c1695b37>] ret_from_kernel_thread+0x1b/0x28
[ 0.171234] [<c1676960>] ? rest_init+0xd0/0xd0
Introduced in "workqueue: convert to idr_alloc()"
Signed-off-by: Artem Savkov <[email protected]>
---
kernel/workqueue.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 8462642..60d58ac 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -463,6 +463,7 @@ static int worker_pool_assign_id(struct worker_pool *pool)
if (ret >= 0)
pool->id = ret;
spin_unlock_irq(&workqueue_lock);
+ idr_preload_end();
} while (ret == -EAGAIN);
return ret < 0 ? ret : 0;
--
1.8.1.5
(cc'ing Stephen and linux-next)
Hello, Artem.
On Wed, Mar 13, 2013 at 09:51:32PM +0400, Artem Savkov wrote:
> Added missing idr_preload_end() call in worker_pool_assign_id().
> Without it preemption stays disabled resulting in lots of "scheduling while
> atomic" BUGs during boot.
...
> Introduced in "workqueue: convert to idr_alloc()"
That patch doesn't use idr_preload(). It looks like the issue is
introduced during linux-next merge of wq/for-3.10 and idr patches in
-mm. Stephen, can you please add idr_preload_end() to the merge
patch?
Once the idr patches land in Linus' tree, I'll resolve the conflict
from wq tree side.
Thanks.
--
tejun
Hi Tejun,
On Wed, 13 Mar 2013 10:57:45 -0700 Tejun Heo <[email protected]> wrote:
>
> (cc'ing Stephen and linux-next)
>
> Hello, Artem.
>
> On Wed, Mar 13, 2013 at 09:51:32PM +0400, Artem Savkov wrote:
> > Added missing idr_preload_end() call in worker_pool_assign_id().
> > Without it preemption stays disabled resulting in lots of "scheduling while
> > atomic" BUGs during boot.
> ...
> > Introduced in "workqueue: convert to idr_alloc()"
>
> That patch doesn't use idr_preload(). It looks like the issue is
> introduced during linux-next merge of wq/for-3.10 and idr patches in
> -mm. Stephen, can you please add idr_preload_end() to the merge
> patch?
Oops, sorry about that. I assume it needs to be added just after the
spin_unlock_irq() but still inside the loop?
> Once the idr patches land in Linus' tree, I'll resolve the conflict
> from wq tree side.
Or you could do what Linus prefers and just tell him how to resolve the
conflict and thereby avoid a back merge or rebase (or provide him with a
separate branch that does the back merge with resolution in addition to
the unmerged branch to pull).
--
Cheers,
Stephen Rothwell [email protected]
Hello,
On Wed, Mar 13, 2013 at 2:51 PM, Stephen Rothwell <[email protected]> wrote:
>> That patch doesn't use idr_preload(). It looks like the issue is
>> introduced during linux-next merge of wq/for-3.10 and idr patches in
>> -mm. Stephen, can you please add idr_preload_end() to the merge
>> patch?
>
> Oops, sorry about that. I assume it needs to be added just after the
> spin_unlock_irq() but still inside the loop?
Yeap. Andrew already has the change, I think.
>> Once the idr patches land in Linus' tree, I'll resolve the conflict
>> from wq tree side.
>
> Or you could do what Linus prefers and just tell him how to resolve the
> conflict and thereby avoid a back merge or rebase (or provide him with a
> separate branch that does the back merge with resolution in addition to
> the unmerged branch to pull).
That part of code is gonna see more changes and I don't wanna build on
top of the deprecated interface, so the back-pull is actually
justified - wq tree actually wants the receive the particular change
to build on top.
Thanks.
--
tejun