From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 112771F4B4 for ; Thu, 24 Sep 2020 17:22:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728585AbgIXRWY (ORCPT ); Thu, 24 Sep 2020 13:22:24 -0400 Received: from pb-smtp2.pobox.com ([64.147.108.71]:54881 "EHLO pb-smtp2.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726915AbgIXRWX (ORCPT ); Thu, 24 Sep 2020 13:22:23 -0400 Received: from pb-smtp2.pobox.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id D2B3F8DE7D; Thu, 24 Sep 2020 13:22:21 -0400 (EDT) (envelope-from junio@pobox.com) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type:content-transfer-encoding; s=sasl; bh=E+riIzjiq2GX XCbpvW/olSEYAGA=; b=iZ4uw3Fud0r90D0hm7+MgecsKeYDUdVjYwn74g238CCi THjF9UUl9rpwItghNpkTRADSBFKZo9pnN4lRQ50AzOP/QfZE/1EXR7BMwEA7HPve e6QIQbPEMGnS+bqhKwbFYlIKVk2NxTqE6I8nbu8zk42Anf8uhYqEQXx3pePr1aU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type:content-transfer-encoding; q=dns; s=sasl; b=ryR3n+ sx3KtWiivmf0Uv2tjxozmWMF99rEzqptAM52s9NXtrlPHbwCwjUNsFUl4MMCQApS CqCZSPzrqV68hi6wyfxMo3H/IOWAG47pqOEhXogJJ/WFv7c9IrRMq9HiPJ26BO8l RhpbnVjxzwbrLXZiJa9IGQLiEJH+3d1PxSZmc= Received: from pb-smtp2.nyi.icgroup.com (unknown [127.0.0.1]) by pb-smtp2.pobox.com (Postfix) with ESMTP id CB4608DE7C; Thu, 24 Sep 2020 13:22:21 -0400 (EDT) (envelope-from junio@pobox.com) Received: from pobox.com (unknown [34.74.119.39]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp2.pobox.com (Postfix) with ESMTPSA id 4D1798DE7B; Thu, 24 Sep 2020 13:22:21 -0400 (EDT) (envelope-from junio@pobox.com) From: Junio C Hamano To: Jeff King Cc: Han-Wen Nienhuys , Han-Wen Nienhuys via GitGitGadget , git , Han-Wen Nienhuys Subject: Re: [PATCH 06/13] reftable: (de)serialization for the polymorphic record type. References: <791f69c000556e93bf5fcfc0ec9304833b12565b.1600283416.git.gitgitgadget@gmail.com> <20200924072151.GC1851751@coredump.intra.peff.net> <20200924073125.GD1851751@coredump.intra.peff.net> Date: Thu, 24 Sep 2020 10:22:20 -0700 In-Reply-To: <20200924073125.GD1851751@coredump.intra.peff.net> (Jeff King's message of "Thu, 24 Sep 2020 03:31:25 -0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 X-Pobox-Relay-ID: 811D4A56-FE8A-11EA-A366-2F5D23BA3BAF-77302942!pb-smtp2.pobox.com Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Jeff King writes: > Then I did the same, but building with -DNO_UNALIGNED_LOADS. The latter > actually ran faster, by a small margin. Here are the hyperfine results: > > [stock] > Time (mean =C2=B1 =CF=83): 6.638 s =C2=B1 0.081 s [User: 6.2= 69 s, System: 0.368 s] > Range (min =E2=80=A6 max): 6.550 s =E2=80=A6 6.841 s 10 runs > > [-DNO_UNALIGNED_LOADS] > Time (mean =C2=B1 =CF=83): 6.418 s =C2=B1 0.015 s [User: 6.0= 58 s, System: 0.360 s] > Range (min =E2=80=A6 max): 6.394 s =E2=80=A6 6.447 s 10 runs > > For casual use as in reftables I doubt the difference is even > measurable. But this result implies that perhaps we ought to just be > using the fallback version all the time. I like that one. One less configurable knob that makes us execute different codepaths is one less thing to be worried about.