From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: [PATCH] t1050-large: replace dd by test-genrandom Date: Tue, 13 Jan 2015 17:38:50 -0500 Message-ID: <20150113223849.GA3144@peff.net> References: <54B5579B.4080607@kdbg.org> <20150113214733.GA16582@peff.net> <54B59D24.7030508@kdbg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Git Mailing List To: Johannes Sixt X-From: git-owner@vger.kernel.org Tue Jan 13 23:38:58 2015 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1YBA6z-0004bU-DP for gcvg-git-2@plane.gmane.org; Tue, 13 Jan 2015 23:38:57 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751539AbbAMWix (ORCPT ); Tue, 13 Jan 2015 17:38:53 -0500 Received: from cloud.peff.net ([50.56.180.127]:34108 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751066AbbAMWiw (ORCPT ); Tue, 13 Jan 2015 17:38:52 -0500 Received: (qmail 20191 invoked by uid 102); 13 Jan 2015 22:38:52 -0000 Received: from Unknown (HELO peff.net) (10.0.1.1) by cloud.peff.net (qpsmtpd/0.84) with SMTP; Tue, 13 Jan 2015 16:38:52 -0600 Received: (qmail 30935 invoked by uid 107); 13 Jan 2015 22:39:13 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.84) with SMTP; Tue, 13 Jan 2015 17:39:13 -0500 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Tue, 13 Jan 2015 17:38:50 -0500 Content-Disposition: inline In-Reply-To: <54B59D24.7030508@kdbg.org> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Tue, Jan 13, 2015 at 11:33:08PM +0100, Johannes Sixt wrote: > BTW, is it the incompressibility where the time is lost or lack of > sparseness of the files? How does the timing change with this patch on > top? Oh, good call. It's the incompressibility. Which makes perfect sense. Once we copy the file into the object database, that copy is not sparse. But in the genrandom version, it _is_ a million times bigger. :) With the patch below, my timings go back to ~0.7s (actually, they seem slightly _better_ on average than what is in "master" now, but there is quite a bit of run-to-run noise, so it may not be meaningful). > diff --git a/t/t1050-large.sh b/t/t1050-large.sh > index f653121..9cf4e0e 100755 > --- a/t/t1050-large.sh > +++ b/t/t1050-large.sh > @@ -9,10 +9,10 @@ test_expect_success setup ' > # clone does not allow us to pass core.bigfilethreshold to > # new repos, so set core.bigfilethreshold globally > git config --global core.bigfilethreshold 200k && > - test-genrandom seed1 2000000 >large1 && > + printf "\0%2000000s" X >large1 && > cp large1 large2 && > cp large1 large3 && > - test-genrandom seed2 2500000 >huge && > + printf "\0%2500000s" Y >huge && > GIT_ALLOC_LIMIT=1500k && > export GIT_ALLOC_LIMIT > ' I think with this squashed in, I have no complaints at all about your patch. -Peff