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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 99B10C33C9E for ; Sat, 11 Jan 2020 11:34:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6814920848 for ; Sat, 11 Jan 2020 11:34:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729082AbgAKLeT (ORCPT ); Sat, 11 Jan 2020 06:34:19 -0500 Received: from gate.crashing.org ([63.228.1.57]:50325 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729006AbgAKLeS (ORCPT ); Sat, 11 Jan 2020 06:34:18 -0500 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 00BBXTQb023225; Sat, 11 Jan 2020 05:33:29 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 00BBXSxW023224; Sat, 11 Jan 2020 05:33:28 -0600 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Sat, 11 Jan 2020 05:33:28 -0600 From: Segher Boessenkool To: Christophe Leroy Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , arnd@arndb.de, tglx@linutronix.de, vincenzo.frascino@arm.com, luto@kernel.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org Subject: Re: Surprising code generated for vdso_read_begin() Message-ID: <20200111113328.GX3191@gate.crashing.org> References: <20200109200733.GS3191@gate.crashing.org> <77a8bf25-6615-6c0a-56d4-eae7aa8a8f09@c-s.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <77a8bf25-6615-6c0a-56d4-eae7aa8a8f09@c-s.fr> User-Agent: Mutt/1.4.2.3i Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Fri, Jan 10, 2020 at 07:45:44AM +0100, Christophe Leroy wrote: > Le 09/01/2020 à 21:07, Segher Boessenkool a écrit : > >It looks like the compiler did loop peeling. What GCC version is this? > >Please try current trunk (to become GCC 10), or at least GCC 9? > > It is with GCC 5.5 > > https://mirrors.edge.kernel.org/pub/tools/crosstool/ doesn't have more > recent than 8.1 Arnd, can you update the tools? We are at 8.3 and 9.2 now :-) Or is this hard and/or painful to do? > With 8.1, the problem doesn't show up. Good to hear that. Hrm, I wonder when it was fixed... Segher