From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: [PATCH] grep: do not do external grep on skip-worktree entries Date: Sun, 03 Jan 2010 23:14:31 -0800 Message-ID: <7v4on2pciw.fsf@alter.siamese.dyndns.org> References: <7vtyv4cpna.fsf@alter.siamese.dyndns.org> <7v7hs09tpi.fsf@alter.siamese.dyndns.org> <87ljgfgbl0.fsf@catnip.gol.com> <877hrzga16.fsf@catnip.gol.com> <7v3a2mzzg4.fsf@alter.siamese.dyndns.org> <20100104053125.GA5083@coredump.intra.peff.net> <7vbphaquwl.fsf@alter.siamese.dyndns.org> <20100104064408.GA7785@coredump.intra.peff.net> <7vhbr2pcsh.fsf@alter.siamese.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jeff King , Linus Torvalds , Miles Bader , Nguyen Thai Ngoc Duy , git@vger.kernel.org To: Junio C Hamano X-From: git-owner@vger.kernel.org Mon Jan 04 08:14:53 2010 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 4.50) id 1NRh9Q-0004Nv-GG for gcvg-git-2@lo.gmane.org; Mon, 04 Jan 2010 08:14:52 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753309Ab0ADHOs (ORCPT ); Mon, 4 Jan 2010 02:14:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753286Ab0ADHOs (ORCPT ); Mon, 4 Jan 2010 02:14:48 -0500 Received: from a-pb-sasl-quonix.pobox.com ([208.72.237.25]:42365 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753288Ab0ADHOr (ORCPT ); Mon, 4 Jan 2010 02:14:47 -0500 Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-quonix.pobox.com (Postfix) with ESMTP id 0A92D8DA49; Mon, 4 Jan 2010 02:14:45 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=to:cc:subject :references:from:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=oaBrU+yHlTIQjkb5rpj1kQBWbuY=; b=rnTgfG 5Adl20COLz6MxjQ/fi2plu/oo8XVY9Xf4IIG4i2IuoYekcLMopJUIGeuYm/oLCL1 OYOOVGf9LQ4PvuplH9CVOsJv3zxX86V3jdTBYmNG6KLTHlh5av4E7iVXEVVHjkZg dZsjZZZM6HFrBg2jX7t6jMhS2sHKbjPPlUmNA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=to:cc:subject :references:from:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=nKW7MPi49W49IFnGBeoxxmSYzmsKnyEt IUpAZz/kG4NhzaTtX4WuGzhDhhA2JzsqJlDBMs+7+qx/LCUD1onDgC3O7rnafp5M RhZCznJMEagSCqai/nVBWiiW/4KqAVupvEVtdq+JkZCIxvEMMu/fkJCprEklKGE0 9OGQdxGzCkQ= Received: from a-pb-sasl-quonix. (unknown [127.0.0.1]) by a-pb-sasl-quonix.pobox.com (Postfix) with ESMTP id 9AB258DA48; Mon, 4 Jan 2010 02:14:39 -0500 (EST) Received: from pobox.com (unknown [68.225.240.211]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by a-pb-sasl-quonix.pobox.com (Postfix) with ESMTPSA id 992C78DA47; Mon, 4 Jan 2010 02:14:32 -0500 (EST) In-Reply-To: <7vhbr2pcsh.fsf@alter.siamese.dyndns.org> (Junio C. Hamano's message of "Sun\, 03 Jan 2010 23\:08\:46 -0800") User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) X-Pobox-Relay-ID: D2958772-F900-11DE-ADF0-9D59EE7EF46B-77302942!a-pb-sasl-quonix.pobox.com Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Junio C Hamano writes: > Jeff King writes: > >> I have to wonder, though...did anybody ever actually profile our >> internal grep to find out _why_ it was so much slower than GNU grep? > > I vaguely recall that somebody fairly competent mentioned that modern grep > implementations are based on DFA engines, but I offhand don't remember if > the discussion had concrete numbers. I found only this one. The author was indeed somebody fairly competent. http://thread.gmane.org/gmane.comp.version-control.git/23798