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 95859C433FE for ; Thu, 29 Sep 2022 15:30:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234955AbiI2Pal (ORCPT ); Thu, 29 Sep 2022 11:30:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235130AbiI2Pag (ORCPT ); Thu, 29 Sep 2022 11:30:36 -0400 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F20C15A17E for ; Thu, 29 Sep 2022 08:30:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=J0QcEJZH30kfY+NXeRpDRgwnLNBhUJp4WTBwQ7RFJsY=; b=j+WVuCijoeRPHWW+1n4j2MYdiN DeWB2p9VOb6ydPgi8oYp1Ec1eQ7GC7ftQ1vXUPFFmqj7aSiXJoL2lBBxh6xjmcPNESrbFshJWdEAK bPOnQix1spOxUhimvEATAmlYnJqRGXhu1S61lzm531RA/GLtd6WyVTKNuuP4iYVAqCLAxW4snIWDJ lmAohSMREX27ohra+buIcyAIsceyglNBQfKJHxunL/QFEB1ehZ/lSZa6uONYPpdn+KR6ivbGTf5OW azgTcKyzz+QBi5wmZUk0IJT2qG4wyUkporLaOs3xGv3J3ZaGXo3SZqxr7MdX4hTCiCcprQFw5mCUn PY5oR0UQ==; Received: from [179.232.144.59] (helo=[192.168.0.5]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1odvUX-00GgKu-LH; Thu, 29 Sep 2022 17:30:25 +0200 Message-ID: <7917fde2-a381-5404-c5ae-6ffd433f85ec@igalia.com> Date: Thu, 29 Sep 2022 12:30:09 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [PATCH] x86/split_lock: Restore warn mode (and add a new one) to avoid userspace regression Content-Language: en-US To: Dave Hansen , tony.luck@intel.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, x86@kernel.org Cc: mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, luto@kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, Fenghua Yu , Joshua Ashton , Paul Gofman , Pavel Machek , Pierre-Loup Griffais , Melissa Wen References: <20220928142109.150263-1-gpiccoli@igalia.com> <24f31510-5b33-ada5-9f0e-117420403e8c@intel.com> <1c742ae1-98cb-a5c1-ba3f-5e79b8861f0b@igalia.com> From: "Guilherme G. Piccoli" In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29/09/2022 12:17, Dave Hansen wrote: > [...] >> Hi Dave, thanks for your response. I really appreciated your reasoning, >> and I think it's a good argument. In the end, adding misery would harm >> the users that are unlikely to be able to fix (or at least, fix quickly) >> the split lock situation, like games or legacy/proprietary code. >> >> I have a revert removing the misery ready and tested, let me know if I >> should submit it. > > I'm a bit of a late arrival to the split lock party, so I'm a bit > hesitant to merge any changes immediately. > OK, agree that we could indeed gather more opinions, like Thomas' and other interested parties. But... > How about we give it a few weeks and see if the current behavior impacts > anyone else? Maybe the best route will be more clear then. ...I disagree in just letting it fly for weeks with all players of God of War 2 running modern Intel chips unable to play in 5.19+ because of this change. Certainly we have more games/applications that are impacted, I just don't think we should wait on having 3 userspace breakages reported, for example, to take an action - why should gamers live with this for an arbitrary amount of time, until others report more issues? Cheers, Guilherme