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 X-Spam-Level: X-Spam-Status: No, score=-5.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2FEEC433ED for ; Tue, 13 Apr 2021 19:13:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0A93613C3 for ; Tue, 13 Apr 2021 19:13:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231812AbhDMTN7 (ORCPT ); Tue, 13 Apr 2021 15:13:59 -0400 Received: from mail.efficios.com ([167.114.26.124]:45122 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229721AbhDMTN5 (ORCPT ); Tue, 13 Apr 2021 15:13:57 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 202A633B5A0; Tue, 13 Apr 2021 15:13:37 -0400 (EDT) Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 1jrIwwa5gEeN; Tue, 13 Apr 2021 15:13:36 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 598C233B416; Tue, 13 Apr 2021 15:13:36 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com 598C233B416 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1618341216; bh=LnwYjKW7sL7zD3ESlP5rxVzHGRgfTuHoEH4jd1qxduc=; h=Date:From:To:Message-ID:MIME-Version; b=KaZlU+9Pjpc1ai5zkcYhZEQnxOHS04U3qEsdYFBxzHolgp9vd/nNVpYSQyesB6OBV 5BY7XIVD9KqpCpWHI+PNb4I0zqra9Md5J0TkMjcYzA9rLUwDk9E3+Iazry6fvCCsGj SYjUy/PRx4C8GsLuCPgdDgD/zZKW35MeIp34/lhBj4s1GWzYY8xcQCQoqR1QL9Kw+3 ShbKTMkmwDyTFnhRZbIM/yojSORR6i53qk4qSLkgcxsAhQbJ/KW+qA6K8ww88zuPlN +o2oUwpWvCgSwMkG4drpQHiguwq2FO4MNaUeuWUDZIcnGpjAmjHIhGPHS45TjSB0ys Zty9C9KYfs7YQ== X-Virus-Scanned: amavisd-new at efficios.com Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id foOJk3EHtdTA; Tue, 13 Apr 2021 15:13:36 -0400 (EDT) Received: from mail03.efficios.com (mail03.efficios.com [167.114.26.124]) by mail.efficios.com (Postfix) with ESMTP id 4AAC833B415; Tue, 13 Apr 2021 15:13:36 -0400 (EDT) Date: Tue, 13 Apr 2021 15:13:36 -0400 (EDT) From: Mathieu Desnoyers To: Eric Dumazet Cc: Eric Dumazet , David Laight , Ingo Molnar , Peter Zijlstra , paulmck , Boqun Feng , Arjun Roy , linux-kernel Message-ID: <64670607.73039.1618341216196.JavaMail.zimbra@efficios.com> In-Reply-To: References: <20210413162240.3131033-1-eric.dumazet@gmail.com> <989543379.72506.1618334454075.JavaMail.zimbra@efficios.com> <1347243835.72576.1618336812739.JavaMail.zimbra@efficios.com> Subject: Re: [PATCH v2 3/3] rseq: optimise rseq_get_rseq_cs() and clear_rseq_cs() MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [167.114.26.124] X-Mailer: Zimbra 8.8.15_GA_3996 (ZimbraWebClient - FF87 (Linux)/8.8.15_GA_4007) Thread-Topic: rseq: optimise rseq_get_rseq_cs() and clear_rseq_cs() Thread-Index: cC6InJlBdTHf/5kUmfCSjYRTTL2VnQ== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- On Apr 13, 2021, at 2:22 PM, Eric Dumazet edumazet@google.com wrote: > On Tue, Apr 13, 2021 at 8:00 PM Mathieu Desnoyers > wrote: >> > >> As long as the ifdefs are localized within clearly identified wrappers in the >> rseq code I don't mind doing the special-casing there. >> >> The point which remains is that I don't think we want to optimize for speed >> on 32-bit architectures when it adds special-casing and complexity to the 32-bit >> build. I suspect there is less and less testing performed on 32-bit >> architectures >> nowadays, and it's good that as much code as possible is shared between 32-bit >> and >> 64-bit builds to share the test coverage. >> > > Quite frankly V1 was fine, I can't really make it looking better. Yes, I'm OK with V1 of that patch. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com