From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752980AbbCEWYq (ORCPT ); Thu, 5 Mar 2015 17:24:46 -0500 Received: from mail-la0-f53.google.com ([209.85.215.53]:34379 "EHLO mail-la0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751477AbbCEWYn (ORCPT ); Thu, 5 Mar 2015 17:24:43 -0500 From: Rasmus Villemoes To: Tejun Heo Cc: Joe Perches , linux-kernel@vger.kernel.org, "Peter Zijlstra \(Intel\)" , Andrew Morton Subject: Re: [RFC] lib/vsprintf.c: Even faster decimal conversion Organization: D03 References: <1424476281-26873-1-git-send-email-linux@rasmusvillemoes.dk> <87r3t3eafm.fsf@rasmusvillemoes.dk> <1425571413.31859.1.camel@perches.com> <20150305161051.GE23912@htj.duckdns.org> X-Hashcash: 1:20:150305:peterz@infradead.org::gWvmpBFrp7aP3Qgg:000000000000000000000000000000000000000002BU1 X-Hashcash: 1:20:150305:tj@kernel.org::hRb1D8OIYsuVFSSY:00002w3P X-Hashcash: 1:20:150305:joe@perches.com::UAwQdNco7XoaqhgM:003DOU X-Hashcash: 1:20:150305:linux-kernel@vger.kernel.org::6QgySlr+ks3gTVtR:0000000000000000000000000000000006FeT X-Hashcash: 1:20:150305:akpm@linux-foundation.org::iEtWnqCZfEKPq1T2:0000000000000000000000000000000000009Vb+ Date: Thu, 05 Mar 2015 23:24:39 +0100 In-Reply-To: <20150305161051.GE23912@htj.duckdns.org> (Tejun Heo's message of "Thu, 5 Mar 2015 11:10:51 -0500") Message-ID: <87egp384m0.fsf@rasmusvillemoes.dk> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 05 2015, Tejun Heo wrote: > On Thu, Mar 05, 2015 at 08:03:33AM -0800, Joe Perches wrote: >> On Thu, 2015-03-05 at 16:22 +0100, Rasmus Villemoes wrote: >> >> > 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. Well, when nobody has responded within a week with even a "not obviously insane, I'll look at it after -rcN/next full moon/...", there's usually little hope of ever getting some feedback. >> Seems sensible enough to me though. > > I'd like to see how this actually affects larger operations - sth > along the line of top consumes D% less CPU cycles w/ N processes - if > for nothing else, just to get the sense of scale, That makes sense. I'll see if I can get some reproducible numbers, but I'm afraid the effect drowns in all the syscall overhead. Which would be a valid argument against touching the code. > I haven't studied the code but looks sensible enough on a glance, so, > FWIW, > > Looks-sensible-by: Tejun Heo Thanks, this was the kind of feedback I was hoping for. Rasmus