From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: [PATCH] Teach "git add" and friends to be paranoid Date: Sun, 21 Feb 2010 22:59:51 -0800 Message-ID: <7vwry5pxg8.fsf@alter.siamese.dyndns.org> References: <20100213162924.GA14623@Knoppix> <37fcd2781002131409r4166e496h9d12d961a2330914@mail.gmail.com> <20100213223733.GP24809@gibbs.hungrycats.org> <20100214011812.GA2175@dpotapov.dyndns.org> <7vljer1gyg.fsf_-_@alter.siamese.dyndns.org> <20100219082813.GB17952@dpotapov.dyndns.org> <7v635tkta7.fsf@alter.siamese.dyndns.org> <7v8waniue8.fsf@alter.siamese.dyndns.org> <20100221072142.GA5829@dpotapov.dyndns.org> <7vhbpas7ut.fsf@alter.siamese.dyndns.org> <20100222033553.GA10191@dpotapov.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Zygo Blaxell , Ilari Liusvaara , Thomas Rast , Jonathan Nieder , git@vger.kernel.org To: Dmitry Potapov X-From: git-owner@vger.kernel.org Mon Feb 22 09:07:39 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 4.69) (envelope-from ) id 1NjSH9-0006KZ-GW for gcvg-git-2@lo.gmane.org; Mon, 22 Feb 2010 08:00:15 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754875Ab0BVHAK (ORCPT ); Mon, 22 Feb 2010 02:00:10 -0500 Received: from a-pb-sasl-quonix.pobox.com ([208.72.237.25]:47980 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753606Ab0BVHAI (ORCPT ); Mon, 22 Feb 2010 02:00:08 -0500 Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-quonix.pobox.com (Postfix) with ESMTP id CC7BA9BBA8; Mon, 22 Feb 2010 02:00:07 -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=r6avOihzu5lzIsvKErUUeucEX7w=; b=r5Ww2u lYhg5+IAkD6mkmiO7d6/D7I0UP0lKKLnaOwQ2Gjdyn3zO55V8wqfl8JatCLvN0Pp /iiphZamr9p4Cg/lY3xTN6yR2lfk10AWSieT9hECmOwZgEKB4vLrfbHMzzlxBrHd zk7BOBMHIvwCWVlUHiUsc8U/JUkPFrOR+Qn3g= 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=lZNzjlmN8dJkAJwSszz/J4TnKm6iTuIO XB0juT8cGTv9MCE8UOac5ndS/96XQAXMTcsUIOkM0QkIaWfwDnG6EQRjh9HTho+F cf1rnzc9pAl/Skr+ImLwCOkzlIWC6KRdcwmVem05XgGzbufR0de69ksaQuocIHwQ USNrRqp4RL8= Received: from a-pb-sasl-quonix. (unknown [127.0.0.1]) by a-pb-sasl-quonix.pobox.com (Postfix) with ESMTP id 0A08A9BB86; Mon, 22 Feb 2010 02:00:01 -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 9C36C9BB83; Mon, 22 Feb 2010 01:59:53 -0500 (EST) In-Reply-To: <20100222033553.GA10191@dpotapov.dyndns.org> (Dmitry Potapov's message of "Mon\, 22 Feb 2010 06\:35\:54 +0300") User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) X-Pobox-Relay-ID: E5245058-1F7F-11DF-8055-D83AEE7EF46B-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: Dmitry Potapov writes: > If you look at speed-up numbers, you can think that the numbers are > unstable, but in fact, the best time in 5 runs does not differ more > than 0.01s between those trials. But because difference for >=128Kb > is 0.05s or less, the accuracy of the above numbers is less than 25%. Then wouldn't it make the following statement... > But overall the outcome is clear -- read() is always a winner. "... a winner, below 128kB; above that the difference is within noise and measurement error"? > It would be interesting to see what difference Nehalem, which has a > smaller but much faster L2 cache than Core 2. It may perform better > at larger sizes up to 256Kb. Interesting.