From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id C9D1F4411A; Fri, 31 May 2024 07:20:00 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 67A664027D; Fri, 31 May 2024 07:20:00 +0200 (CEST) Received: from mail.lysator.liu.se (mail.lysator.liu.se [130.236.254.3]) by mails.dpdk.org (Postfix) with ESMTP id 3B2194027C for ; Fri, 31 May 2024 07:19:46 +0200 (CEST) Received: from mail.lysator.liu.se (localhost [127.0.0.1]) by mail.lysator.liu.se (Postfix) with ESMTP id 5C66FF775 for ; Fri, 31 May 2024 07:19:45 +0200 (CEST) Received: by mail.lysator.liu.se (Postfix, from userid 1004) id 4BAD5F774; Fri, 31 May 2024 07:19:45 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 4.0.0 (2022-12-13) on hermod.lysator.liu.se X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=ALL_TRUSTED,AWL, T_SCC_BODY_TEXT_LINE autolearn=disabled version=4.0.0 X-Spam-Score: -1.3 Received: from [192.168.1.59] (h-62-63-215-114.A163.priv.bahnhof.se [62.63.215.114]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.lysator.liu.se (Postfix) with ESMTPSA id F35CDF826; Fri, 31 May 2024 07:19:42 +0200 (CEST) Message-ID: Date: Fri, 31 May 2024 07:19:41 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC v2] eal: provide option to use compiler memcpy instead of RTE To: Bruce Richardson , Stephen Hemminger Cc: =?UTF-8?Q?Mattias_R=C3=B6nnblom?= , dev@dpdk.org, =?UTF-8?Q?Morten_Br=C3=B8rup?= References: <20240527111151.188607-1-mattias.ronnblom@ericsson.com> <20240528074354.190779-1-mattias.ronnblom@ericsson.com> <738e376c-c5b6-44dc-ad51-00f40d2ea6b5@lysator.liu.se> <20240528075936.2110c31c@hermes.local> Content-Language: en-US From: =?UTF-8?Q?Mattias_R=C3=B6nnblom?= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Virus-Scanned: ClamAV using ClamSMTP X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On 2024-05-28 17:09, Bruce Richardson wrote: > On Tue, May 28, 2024 at 07:59:36AM -0700, Stephen Hemminger wrote: >> On Tue, 28 May 2024 10:19:15 +0200 >> Mattias Rönnblom wrote: >> >>>> >>> >>> I've tested this patch some with DSW micro benchmarks, and the result is >>> a 2.5% reduction of the DSW+testapp overhead with cc/libc memcpy. GCC 11.4. >>> >>> We've also run characteristic test suite of a large, real world app. >>> Here, we saw no effect. GCC 10.5. >>> >>> x86_64 in both cases (Skylake and Raptor Lake). >>> >>> Last time we did the same, there were a noticeable performance >>> degradation in both the above cases. >>> >>> This is not a lot of data points, but I think it we should consider >>> making the custom RTE memcpy() implementations optional in the next >>> release, and if no-one complains, remove the implementations in the next >>> release. >> >> Lets go farther. >> >> 1. Announce that rte_memcpy will be marked deprecated in 24.11 release >> >> 2. In 24.11 do a global replace of rte_memcpy on the tree. >> And mark rte_memcpy as deprecated. >> >> 3. In 25.11 it can go away. > > While I'd like us to be able to do so, I believe that to be premature. We > need to see where/if there are regressions first, and see about fixing > them. > > /Bruce Should I turn this RFC into a PATCH? Is use_cc_memcpy a good name for the configuration parameter?