From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] target: Pass through I/O topology for block backstores Date: Fri, 11 Oct 2013 11:03:48 -0700 Message-ID: <20131011180348.GA21030@infradead.org> References: <1381513206-8155-1-git-send-email-agrover@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1381513206-8155-1-git-send-email-agrover@redhat.com> Sender: target-devel-owner@vger.kernel.org To: Andy Grover Cc: target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, martin.petersen@oracle.com List-Id: linux-scsi@vger.kernel.org On Fri, Oct 11, 2013 at 10:40:06AM -0700, Andy Grover wrote: > In addition to block size (already implemented), passing through > alignment offset, logical-to-phys block exponent, I/O granularity and > optimal I/O length will allow initiators to properly handle layout on > LUNs with 4K block sizes. > > Tested with various weird values via scsi_debug module. > > One thing to look at with this patch is the new block limits values -- > instead of granularity 1 optimal 8192, Lio will now be returning whatever > the block device says, which may affect performance. Wouldn't it be nicer to have a single method that takes a whole queue_limits structure?