From: Garg Vakul-B16394 Subject: RE: [PATCH][RFC] crypto: tcrypt - Ahash tests changed to run in parallel. Date: Thu, 10 Jan 2013 06:49:23 +0000 Message-ID: <065BBB7616BCE543832A2EF096986B94150EC2@039-SN2MPN1-011.039d.mgd.msft.net> References: <1357123173-32534-1-git-send-email-vakul@freescale.com> <20130105182556.87853b23jydihzk0@www.dalek.fi> <065BBB7616BCE543832A2EF096986B9414EFE5@039-SN2MPN1-011.039d.mgd.msft.net> <20130109154552.4163137574bb7de915017e21@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Cc: Jussi Kivilinna , "linux-crypto@vger.kernel.org" To: Phillips Kim-R1AAHA Return-path: Received: from co9ehsobe002.messaging.microsoft.com ([207.46.163.25]:57246 "EHLO co9outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932096Ab3AJGtb convert rfc822-to-8bit (ORCPT ); Thu, 10 Jan 2013 01:49:31 -0500 In-Reply-To: <20130109154552.4163137574bb7de915017e21@freescale.com> Content-Language: en-US Sender: linux-crypto-owner@vger.kernel.org List-ID: Hello Kim > -----Original Message----- > From: Phillips Kim-R1AAHA > Sent: Thursday, January 10, 2013 3:16 AM > To: Garg Vakul-B16394 > Cc: Jussi Kivilinna; linux-crypto@vger.kernel.org > Subject: Re: [PATCH][RFC] crypto: tcrypt - Ahash tests changed to run in > parallel. > > On Sat, 5 Jan 2013 17:14:13 +0000 > Garg Vakul-B16394 wrote: > > > > From: Jussi Kivilinna [mailto:jussi.kivilinna@mbnet.fi] > > > Sent: Saturday, January 05, 2013 9:56 PM > > > > > > Quoting Vakul Garg : > > > > > > > This allows to test & run multiple parallel crypto ahash contexts. > > > > Each of the test vector under the ahash speed test template is > > > > started under a separate kthread. > > > > > > Why you want to do this? > > > > In its current form, we cannot test multiple simultaneous crypto > sessions with tcrypt. > > Crypto offload hardware accelerators are usually capable of handling > multiple session in parallel. > > This patch allows to load such hardware. > > tcrypt can currently test offload engines with multiple single-session > async requests. So to test multiple _session_ requests, why isn't the > change to tcrypt simply to alternate keys in the request loop, as opposed > to what this patch does, i.e. > adding separate kthreads? The number of sessions/keys to alternate can > be added as a module parameter. > > > Even if offload accelerators are not present, multiple crypto sessions > can execute in parallel on Multicore. > > I think that's more in the area of PCRYPT. > > > > Does not this change make tcrypt give inconsistent results? > > > > > > > Based on kernel scheduling of threads, this change can make tcrypt give > varying results in different runs. > > For consistent results, we can use existing synchronous mode crypto > sessions. > > see above. I'm not sure, but I think multithreading tcrypt should be > left to the parallel crypto engine (PCRYPT) and Software async crypto > daemon (CRYPTD). [VG] IIUC, PCRYPT and CRYPTD provides infrastructure to execute crypto contexts under threads to achieve different things. PCRYPT allows multiple crypto requests from a transform to execute in parallel. CRYPTD provides a daemon which executes crypto requests. It is more like crypto hardware accelerator running in software (e.g. on a certain core of Multicore processor). My proposal is to add capability in tcrypt to launch multiple parallel crypto transforms. Currently, only one transform is active at any point of time. > > Kim