Re: block: BUG: using smp_processor_id() in preemptible [00000000]code

From: Jens Axboe
Date: Tue Jul 26 2011 - 01:26:23 EST


On 2011-07-26 06:49, Ming Lei wrote:
> Hi,
>
> The bug is observed in -next-20110725, follows the stack trace[1], and
> seems the attachment patch can fix the bug.

Does this work, too? We don't necessarily need the CPU stable, but
spewing debug output isn't very nice.

diff --git a/block/blk-core.c b/block/blk-core.c
index f8cb099..f925581 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1283,7 +1283,7 @@ get_rq:

if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) ||
bio_flagged(bio, BIO_CPU_AFFINE))
- req->cpu = smp_processor_id();
+ req->cpu = raw_smp_processor_id();

plug = current->plug;
if (plug) {

--
Jens Axboe

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