From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Thornber Subject: Re: DM limits setup Date: Mon, 5 Jan 2015 10:21:52 +0000 Message-ID: <20150105102151.GC11818@debian> References: Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: doug@easyco.com, device-mapper development List-Id: dm-devel.ids On Wed, Dec 31, 2014 at 02:10:52PM -0800, Doug Dumitru wrote: > Hello all, > > I have a test dm target module that I use to validate storage subsystems > for data accuracy. It basically builds weak hashes for every sector of a > device when written, and validates these hashes when the sector is read > back. Ugly memory usage, but it is just a test tool. > > I can deploy this with an iterator target and it will take on the limits of > the device underneath, or I can skip the iterator target and get limits at > 2048 sectors. What I would like to do is set the limit manually. I know > this is "really bad program design", but again, this is a test tool and not > anything for production use. > > Can anyone point me at an example of where the limits are setup explicitly. Hi Doug, This sounds like a useful target for testing, any chance you could post it here when you finish it please? dm-thin does lots of tweaking of limits, so that's probably the best one to look at: https://github.com/jthornber/linux-2.6/blob/thin-dev/drivers/md/dm-thin.c#L3707 - Joe