From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: CONFIG_DM_MQ_DEFAULT makes my kernel unhappy.. Date: Sat, 25 Apr 2015 08:37:32 -0700 Message-ID: <20150425153732.GA10612@infradead.org> References: <20150425092358.GA15550@infradead.org> <20150425152856.GB28453@redhat.com> 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: <20150425152856.GB28453@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Mike Snitzer Cc: Christoph Hellwig , dm-devel@redhat.com List-Id: dm-devel.ids On Sat, Apr 25, 2015 at 11:28:57AM -0400, Mike Snitzer wrote: > On Sat, Apr 25 2015 at 5:23am -0400, > Christoph Hellwig wrote: > > > Running dm-mpath against a tcm_loop target with two ALUA paths makes > > the kernel very unhappy when CONFIG_DM_MQ_DEFAULT is set. Without it > > it's perfectly happy. > > Wonder if commit 63a4f065ec ("dm: fix add_disk() NULL pointer due to > race with free_dev()") left something not quite right relative to > blk-mq? Or maybe this is a problem confined to blk-mq itself. I'll give it a spin. > What were you actually testing when this happened? Were you failing > paths under IO load or something? This happened on the initial udev-direct scan of the devices. > Also, which upstream commit was your tree based on? Did you have any > non-upstream patches applied that I should be aware of? Latest Linus tree as of this morning.