Hi Jens,
while hunting yet another queue stall I've been looking at
__blk_mq_tag_busy():
bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
{
if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) &&
!test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
atomic_inc(&hctx->tags->active_queues);
return true;
}
Is this some subtle usage of bitops (and I just didn't grasp it) or is
the first test_bit() pointless?
If the former I _really_ would like to have some comments on why this is
required.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
[email protected] +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-block" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
