From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4A8DEB64D9 for ; Tue, 27 Jun 2023 22:50:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229718AbjF0Wuz (ORCPT ); Tue, 27 Jun 2023 18:50:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229647AbjF0Wuw (ORCPT ); Tue, 27 Jun 2023 18:50:52 -0400 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 928C52941 for ; Tue, 27 Jun 2023 15:50:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1687906249; x=1719442249; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=rk1Zya4YN7L4kSRUevCkoBKyaGg7P8Q144xFDaiTCVY=; b=eY6Z8GQ6tZ3KA7QdWO6XQmThCc8Grr3iOTOCymEuYGfpEv2UnSKyltGn wbz20FoGIVfor5U4e1vFKhzcAQAENw6PsATZzCXTtanwfCr+FalrHxi26 n9uEVliBHZI29yzan/N3xVUxQaTwJGAdFHHeXQuCp/n4DalLKOVWuTkeG 0QCDqbzrg780mkyA/fGyOjm8i3oiSx6Vh02MX3rKTmpc/KL1QpIkdcbhc 1Bpwh4AL2h3iHcT+3hOXhVFDwumPNtIoquLt0erjfbO2WlLtFdYwKFGMS C1SM4ZjpTHtfBxRmQbJd9GfPlsSwGj01j7hXnhmVXtZzrdce5TFlvp9oO g==; X-IronPort-AV: E=McAfee;i="6600,9927,10754"; a="346460977" X-IronPort-AV: E=Sophos;i="6.01,163,1684825200"; d="scan'208";a="346460977" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2023 15:50:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10754"; a="890837171" X-IronPort-AV: E=Sophos;i="6.01,163,1684825200"; d="scan'208";a="890837171" Received: from avandeve-mobl1.amr.corp.intel.com (HELO [10.209.78.231]) ([10.209.78.231]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2023 15:50:48 -0700 Message-ID: <51f58d51-d5bf-79a2-a32a-e6849a118123@linux.intel.com> Date: Tue, 27 Jun 2023 15:50:48 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [GIT PULL] x86/misc for 6.5 Content-Language: en-US To: Linus Torvalds Cc: Borislav Petkov , Noah Goldstein , Dave Hansen , x86-ml , lkml References: <20230627110038.GCZJrBVqu/4BfdyBeN@fat_crate.local> <1982e4b4-3858-d456-6c90-92782b95726a@linux.intel.com> From: Arjan van de Ven In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/27/2023 3:43 PM, Linus Torvalds wrote: > On Tue, 27 Jun 2023 at 15:25, Linus Torvalds > wrote: >> >> I don't know what the rules are - and some of the functions you test >> seem actively buggy (ie not handling alignment right etc). > > Oh. And you *only* test the 40-byte case. That seems a bit bogus. > > If I change the packet size from 40 to 1500, I get > > 02: 185.1 / 186.4 cycles (8b414316) Upcoming linux kernel version > 04: 184.9 / 186.5 cycles (8b414316) Specialized to size 40 > 06: 107.3 / 117.2 cycles (8b414316) New version > 22: 185.6 / 186.5 cycles (8b414316) Odd-alignment handling removed > > which seems unexpectedly bad for the other versions. > I'm not surprised though; running 2 parallel streams (where one stream has a fixed zero as input, so can run OOO any time) .. can really have a performance change like this