From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 00/17] SCSI data path micro-optimizations Date: Wed, 05 Feb 2014 04:39:30 -0800 Message-ID: <20140205123930.150608699@bombadil.infradead.org> Return-path: Received: from bombadil.infradead.org ([198.137.202.9]:53183 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751187AbaBEMkY (ORCPT ); Wed, 5 Feb 2014 07:40:24 -0500 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Jens Axboe , James Bottomley , Nicholas Bellinger Cc: linux-scsi@vger.kernel.org This series contains various optimizations for the SCSI data I/O path. They increase the number of IOPS seen with iSCSI or SRP between 2% and 3.5% in workloads that previously hit the host_lock hard. While this isn't a lot it now fully shifts the contention to the queue_lock, which will get out of the way later when the SCSI midlayer is converted to use the blk-mq infrastructure. Testing has been limited on virtio_scsi, libata, iscsi and srp and more feedback is as always welcome. This work was sponsored by the ION division of Fusion IO.