From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from v6.tansi.org (ns.km31936-01.keymachine.de [87.118.116.4]) by mail.server123.net (Postfix) with ESMTP for ; Mon, 30 Mar 2015 18:52:07 +0200 (CEST) Received: from gatewagner.dyndns.org (77-57-54-224.dclient.hispeed.ch [77.57.54.224]) by v6.tansi.org (Postfix) with ESMTPA id 9F8E120DC1FA for ; Mon, 30 Mar 2015 18:52:05 +0200 (CEST) Date: Mon, 30 Mar 2015 18:52:05 +0200 From: Arno Wagner Message-ID: <20150330165205.GA2599@tansi.org> References: <20150325200150.GA2747@darwin.bork.org> <55131FDE.204@gmail.com> <20150326025449.GA17164@tansi.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [dm-crypt] Larger encryption requests from dm-crypt List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: dm-crypt@saout.de On Fri, Mar 27, 2015 at 14:40:28 CET, Martin Hicks wrote: > On Wed, Mar 25, 2015 at 10:54 PM, Arno Wagner wrote: [...] > >> (Why it is so slow for 512bytes sectors? Isn't it problem of hw? > >> The overhead should not be such high...) > > > > I am wondering that too. This hardware may have a really, > > really slow key-setup, far slower than the crypto merits. > > Would not be the first time that non-crypto people messed > > something like this up by faulty assumptions on how things > > are used. > > I'm not sure. I just assumed it was all the overhead of request queue > management, servicing interrupts, spinlocks, in addition to the > hardware setup time. Doing 512byte sectors results in 80000+ > interrupts/sec. Possibly. Although a key-setup should take longer than handling an interrupt and even 80k/sec interrupts should not cause much load or slowdown. Of course, it is possible that this platform is really bad at handling interrupts. > Anyways, I wasn't fighting for inclusion of this patch, just providing > it in case anyone else is looking at Talitos' performance. I will > take a look at the changes in v4.0 kernel and hopefully adapt this > patch to the changes. That is entirely fine. And thanks for posting the info. Arno > Thanks for your comments, > mh > > -- > Martin Hicks P.Eng. | mort@bork.org > Bork Consulting Inc. | +1 (613) 266-2296 > _______________________________________________ > dm-crypt mailing list > dm-crypt@saout.de > http://www.saout.de/mailman/listinfo/dm-crypt -- Arno Wagner, Dr. sc. techn., Dipl. Inform., Email: arno@wagner.name GnuPG: ID: CB5D9718 FP: 12D6 C03B 1B30 33BB 13CF B774 E35C 5FA1 CB5D 9718 ---- A good decision is based on knowledge and not on numbers. -- Plato If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier