From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [dm-devel] DM-CRYPT: Scale to multiple CPUs v3 Date: Sun, 10 Oct 2010 22:20:31 +0200 Message-ID: <20101010202031.GD21681@basil.fritz.box> References: <20101010130842.GE8256@basil.fritz.box> <4CB1DD1A.5080906@redhat.com> <20101010162257.GA1272@redhat.com> <20101010170151.GD28828@agk-dp.fab.redhat.com> <20101010174454.GA21681@basil.fritz.box> <20101010181736.GE28828@agk-dp.fab.redhat.com> <20101010185100.GB21681@basil.fritz.box> <20101010190734.GH28828@agk-dp.fab.redhat.com> <20101010191640.GC21681@basil.fritz.box> <4CB21492.8050101@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4CB21492.8050101@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Milan Broz Cc: Andi Kleen , Mike Snitzer , Andi Kleen , device-mapper development , pedrib@gmail.com, linux-kernel@vger.kernel.org List-Id: dm-devel.ids > But previously, there were threads per device, so if one IO thread blocks, > others stacked mappings can continue > Now I see possibility for deadlock there because we have one io thread now > (assuming that 1 CPU situation Alasdair mentioned). That path calls the crypto worker thread, not the IO worker thread? crypto worker should be fine here, only IO worker would be a problem I think because crypto doesn't really block on nested IO. -Andi