Re: scsi-mq V2

From: Jens Axboe
Date: Wed Jul 09 2014 - 15:38:19 EST

On 2014-07-09 18:39, Douglas Gilbert wrote:
On 14-07-08 10:48 AM, Christoph Hellwig wrote:
On Wed, Jun 25, 2014 at 06:51:47PM +0200, Christoph Hellwig wrote:
Changes from V1:
- rebased on top of the core-for-3.17 branch, most notable the
scsi logging changes
- fixed handling of cmd_list to prevent crashes for some heavy
- fixed incorrect handling of !target->can_queue
- avoid scheduling a workqueue on I/O completions when no queues
are congested

In addition to the patches in this thread there also is a git
available at:

git:// scsi-mq.2

I've pushed out a new scsi-mq.3 branch, which has been rebased on the
latest core-for-3.17 tree + the "RFC: clean up command setup" series
from June 29th. Robert Elliot found a problem with not fully zeroed
out UNMAP CDBs, which is fixed by the saner discard handling in that

There is a new patch to factor the code from the above series for
blk-mq use, which I've attached below. Besides that the only changes
are minor merge fixups in the main blk-mq usage patch.

Be warned: both Rob Elliott and I can easily break
the scsi-mq.3 branch. It seems as though a regression
has slipped in. I notice that Christoph has added a
new branch called "scsi-mq.3-no-rebase".

Rob/Doug, those issues look very much like problems in the aio code. Can either/both of you try with:


reverted (in that order) and see if that changes anything.

Jens Axboe

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