Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756796AbaGNTPV (ORCPT ); Mon, 14 Jul 2014 15:15:21 -0400 Received: from casper.infradead.org ([85.118.1.10]:53704 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755857AbaGNTPP (ORCPT ); Mon, 14 Jul 2014 15:15:15 -0400 Date: Mon, 14 Jul 2014 21:15:04 +0200 From: Peter Zijlstra To: Tim Chen Cc: Herbert Xu , "H. Peter Anvin" , "David S.Miller" , Ingo Molnar , Chandramouli Narayanan , Vinodh Gopal , James Guilford , Wajdi Feghali , Jussi Kivilinna , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 6/7] sched: add function nr_running_cpu to expose number of tasks running on cpu Message-ID: <20140714191504.GO9918@twins.programming.kicks-ass.net> References: <1405110784.2970.655.camel@schen9-DESK> <20140714101611.GS9918@twins.programming.kicks-ass.net> <1405354214.2970.663.camel@schen9-DESK> <20140714161432.GC9918@twins.programming.kicks-ass.net> <1405357534.2970.701.camel@schen9-DESK> <20140714181738.GI9918@twins.programming.kicks-ass.net> <1405364908.2970.729.camel@schen9-DESK> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="XZq0mbLCR4KNTYFe" Content-Disposition: inline In-Reply-To: <1405364908.2970.729.camel@schen9-DESK> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --XZq0mbLCR4KNTYFe Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jul 14, 2014 at 12:08:28PM -0700, Tim Chen wrote: > On Mon, 2014-07-14 at 20:17 +0200, Peter Zijlstra wrote: > > Your multi-buffer thing isn't generic either, it seems lmiited to sha1. >=20 > We actually have many other multi-buffer crypto algorithms already > published for encryption and other IPSec usages. So=20 > multi-buffer algorithm is not just limited to SHA1. > We hope to port those to the kernel crypto library eventually. > http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/= fast-multi-buffer-ipsec-implementations-ia-processors-paper.pdf=20 That's all nice and such; but the code as I've seen in these patches is very much sha1 specific. The mb part isn't separated out. > > It does not reuse padata,=20 > padata tries to speed things up by parallelizing jobs to *multiple* > cpus. Whereas multi-buffer tries to speed things up by speeding things > up by using multiple data lanes in SIMD register in a *single* cpu. > These two usages are complementary but not the same. And if its single cpu, wth do you need that nr_running thing for another cpu for? Also, this difference wasn't clear to me. I still loathe all the async work, because it makes a mockery of accounting etc.. but that's a story for another day I suppose :-( --XZq0mbLCR4KNTYFe Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTxCw4AAoJEHZH4aRLwOS6TY4P/AklVJoTWm/aJpCS6h4zP3fX a0Bt8E5dDKVvc6km38vZEHvdrSSdi4JC2IksbGSLB5MPMVwxbtQqQ32Tz8w6BKOu W/mAIOACmApufx9url5VWgEGDjehoqIh2zcCbik5P9bG17fVU7w/IdOalstu0+KP s28LgiIR+iMxaNDVfHt4lus2JFXI0lRg2KlgqEv1sX36kjmqApZkAPRlFW1M4zlr Go9XZe6ANN46f4ffe123D7VGAl0DJmXMRf1kFvyRP4V88W2COIYxsnwnEcEYTGFB gWH05NufrQgNvSC8jhCktZlHx7yuDUrc1+v4IKM76uGSFyTIsbee+YpiLzJRd/Pu BcPlVf3UvxM3bfgCPoYUNiGgTXVGfaPGScL1yZSuAWmckvEKm2Xn2n1VyPjXxOuK NyGGwwjXcO0hw0oP/dqzmcrECLBsmnNoUVtz0WB0GPG5NEXS9WVJpihRlLoyt1zT 2lh4Y//ZhHMfCPoFccwfzWMQ32vZUzreyaPTYfp+OEAaakUPDF16Y3CMHvSFVyjd EYtW6+QHUQ7TnIQ02egHl2bLQ7g+heaFhsFl0DbqdrN/yoCJ4k9wu9Dg/54fosba FkpCqZlmdSzbMOygEwsGab054nR71DyxdhdXp4dzolKpozWkXCecof94C5fMmQnO 3aWLkTYlJK+7wi807Sxx =6dIe -----END PGP SIGNATURE----- --XZq0mbLCR4KNTYFe-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/