From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: [RFC/PATCH 2/2] tests: scrub environment of GIT_* variables Date: Tue, 15 Mar 2011 16:01:03 -0400 Message-ID: <20110315200103.GA3953@sigill.intra.peff.net> References: <20110315064909.GA25738@elie> <20110315070445.GC29530@elie> <20110315073718.GB11754@sigill.intra.peff.net> <20110315100846.GB3923@elie> <20110315101045.GD3923@elie> <7v4o74b8r5.fsf@alter.siamese.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Vicent Marti , Jonathan Nieder , git@vger.kernel.org, Petr Onderka To: Junio C Hamano X-From: git-owner@vger.kernel.org Tue Mar 15 21:01:22 2011 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1PzaQg-0008AO-PJ for gcvg-git-2@lo.gmane.org; Tue, 15 Mar 2011 21:01:19 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757738Ab1COUBI (ORCPT ); Tue, 15 Mar 2011 16:01:08 -0400 Received: from 99-108-226-0.lightspeed.iplsin.sbcglobal.net ([99.108.226.0]:47183 "EHLO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757474Ab1COUBG (ORCPT ); Tue, 15 Mar 2011 16:01:06 -0400 Received: (qmail 25585 invoked by uid 107); 15 Mar 2011 20:01:39 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) (smtp-auth username relayok, mechanism cram-md5) by peff.net (qpsmtpd/0.84) with ESMTPA; Tue, 15 Mar 2011 16:01:39 -0400 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Tue, 15 Mar 2011 16:01:03 -0400 Content-Disposition: inline In-Reply-To: <7v4o74b8r5.fsf@alter.siamese.dyndns.org> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Tue, Mar 15, 2011 at 10:20:46AM -0700, Junio C Hamano wrote: > I am perfectly fine with the use of perl but do we know the "perl" binary > found on $PATH (as opposed to $PERL_PATH) is good to use for this purpose? > The features used in the scriptlet seem so bread-and-butter that I don't > think it would make too much of a difference, but we may want to be > consistent. We already make the assumption elsewhere in the tests that perl in $PATH is some minimal sane version (which probably means some version of perl5 in practice). This little script looks like it should run under any perl5 to me. > I personally think USE_LOOKUP outlived its usefulness. It was meant to be > an easy way to experiment if the sha1_entry_pos() lookup gives better > performance while looking up a pack entry, to choose one implementation > and discard the other, but I don't think anybody actually did meaningful > benchmarks to decide which one to keep. > > Perhaps we should discard the codepath USE_LOOKUP turns on, which I > suspect hasn't been exercised since v1.5.6 days by anybody. An obvious > alternative is for somebody to try using USE_LOOKUP and see if it really > gives a better performance with large packs (and if so, always use it and > discard the other codepath). Vicent asked me about it the other day with respect to doing something similar in libgit2. I tried a few basic things and never ended up getting any substantially different timing (or even page faults) between the two strategies. Vicent, did you do any timings where it made a difference? -Peff