Re: [PATCH 4/6] mpt2sas: store scsi io tracker data in the scsi request

From: Christoph Hellwig
Date: Mon Apr 13 2015 - 05:49:51 EST

On Tue, Apr 07, 2015 at 11:18:38AM -0600, Jens Axboe wrote:
> Instead of storing the IO tracker structure in a separate list
> that we need to pop/push to on every submit and complete (and
> lock), store it in the pdu associated with a request. This is
> possible on scsi-mq only, and further cuts the spinlock associated
> time for higher IOPS IO workloads. At 100K IOPS, this effectively
> cuts the locking time in half.

As mentioned before please call scsi_init_shared_tag_map and use your
new code path for the !mq case as well.
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