From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757421AbbCEQDj (ORCPT ); Thu, 5 Mar 2015 11:03:39 -0500 Received: from smtprelay0089.hostedemail.com ([216.40.44.89]:32884 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756915AbbCEQDi (ORCPT ); Thu, 5 Mar 2015 11:03:38 -0500 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::::,RULES_HIT:41:355:379:541:599:800:960:988:989:1260:1277:1311:1313:1314:1345:1359:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:1801:2393:2553:2559:2562:2828:3138:3139:3140:3141:3142:3352:3622:3865:3867:3871:3872:3873:3874:4321:4605:5007:6119:6261:7903:9121:10004:10400:10848:11026:11232:11233:11658:11914:12517:12519:12555:12663:12740:13069:13311:13357:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: cable03_3c66919df4913 X-Filterd-Recvd-Size: 2014 Message-ID: <1425571413.31859.1.camel@perches.com> Subject: Re: [RFC] lib/vsprintf.c: Even faster decimal conversion From: Joe Perches To: Rasmus Villemoes Cc: linux-kernel@vger.kernel.org, "Peter Zijlstra (Intel)" , Tejun Heo , Andrew Morton Date: Thu, 05 Mar 2015 08:03:33 -0800 In-Reply-To: <87r3t3eafm.fsf@rasmusvillemoes.dk> References: <1424476281-26873-1-git-send-email-linux@rasmusvillemoes.dk> <87r3t3eafm.fsf@rasmusvillemoes.dk> Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.12.10-0ubuntu1~14.10.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2015-03-05 at 16:22 +0100, Rasmus Villemoes wrote: > On Sat, Feb 21 2015, Rasmus Villemoes wrote: > > > [...] decimal conversion [...] it does indeed seem like there is > > something to be gained, especially on 64 bits. > > > > $ ./test64 > > Distribution Function Cycles/conv Conv/1 sec > > uniform([10, 2^64-1]) linux_put_dec 127.72 23047567 > > uniform([10, 2^64-1]) rv_put_dec 60.73 45932786 > > +/- -52.45% +99.30% > [...] > > 3 + neg_binom(0.50) linux_put_dec 16.85 159560933 > > 3 + neg_binom(0.50) rv_put_dec 12.59 204607570 > > +/- -25.31% +28.23% > > I'm assuming the underwhelming response means NAK. Dunno why you assume that, sometimes it just takes awhile for people to look at non-critical, infrequent optimization changes like this. Seems sensible enough to me though.