From owner-freebsd-current@FreeBSD.ORG Sat Aug 14 08:44:34 2010 Return-Path: Delivered-To: current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B00CA10656A3; Sat, 14 Aug 2010 08:44:34 +0000 (UTC) (envelope-from danny@cs.huji.ac.il) Received: from kabab.cs.huji.ac.il (kabab.cs.huji.ac.il [132.65.16.84]) by mx1.freebsd.org (Postfix) with ESMTP id 62D348FC0A; Sat, 14 Aug 2010 08:44:34 +0000 (UTC) Received: from pampa.cs.huji.ac.il ([132.65.80.32]) by kabab.cs.huji.ac.il with esmtp id 1OkBiZ-0004f1-0L; Sat, 14 Aug 2010 11:03:51 +0300 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2 To: "Sean C. Farley" In-reply-to: References: <4C6505A4.9060203@FreeBSD.org> <4C650B75.3020800@FreeBSD.org> Comments: In-reply-to "Sean C. Farley" message dated "Fri, 13 Aug 2010 10:41:35 -0500." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sat, 14 Aug 2010 11:03:50 +0300 From: Daniel Braniss Message-ID: Cc: Gabor Kovesdan , current@FreeBSD.org Subject: Re: Official request: Please make GNU grep the default X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 14 Aug 2010 08:44:34 -0000 > This message is in MIME format. The first part should be readable text, > while the remaining parts are likely unreadable without MIME-aware tools. > > --56599777-398594934-1281714095=:35204 > Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed > > On Fri, 13 Aug 2010, Gabor Kovesdan wrote: > > > Em 2010.08.13. 10:43, Doug Barton escreveu: > >> My reason is simple, performance. While doing some portmaster work > >> recently I was regression testing some changes I made to the --index* > >> options and noticed that things were dramatically slower than the > >> last time I tested those features. Thinking that I had made a > >> programming mistake I dug into my code, and while the regexps that I > >> was using could be tuned for slightly better performance the problem > >> was not in my code. I then installed textproc/gnugrep to compare, > >> and the differences were very dramatic using a highly pessimized test > >> case (finding a match on the last line of INDEX). The script I used > >> to test is at http://people.freebsd.org/~dougb/grep-time-trial.sh.txt > >> and a typical result was: > >> > >> GNU grep > >> Elapsed time: 2 seconds > >> > >> BSD grep > >> Elapsed time: 47 seconds > >> > > Ok, I'll take care of this soon, and make GNU grep default, again with > > a knob to build BSD grep. I agree with you that we cannot allow such a > > big performance drawback but I my measures only showed significant > > differences for very big searches and I didn't imagine that it could > > add up to such a big diference. I'm sorry for the bad decision I took > > making it default. > > This should trim some time off BSD grep. It removes the lock/unlock for > each fgetc() by locking/unlocking the file once. stdio can be slow. > > You probably want to replace flockfile() with ftrylockfile() if threads > will be involved at some point (threading or making a libgrep that may > be used in a threaded process). why would you want to lock a file for reading anyways? BTW, back in the jurasic age, ATT/Bell had this poster: Reach out and GREP someone! danny