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 10CC9C433FE for ; Thu, 6 Oct 2022 09:04:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231304AbiJFJE0 (ORCPT ); Thu, 6 Oct 2022 05:04:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230466AbiJFJEY (ORCPT ); Thu, 6 Oct 2022 05:04:24 -0400 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4A8261B39 for ; Thu, 6 Oct 2022 02:04:22 -0700 (PDT) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 6A3E71C0017; Thu, 6 Oct 2022 11:04:20 +0200 (CEST) Date: Thu, 6 Oct 2022 11:04:18 +0200 From: Pavel Machek To: "Luck, Tony" Cc: "Guilherme G. Piccoli" , "tglx@linutronix.de" , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "hpa@zytor.com" , "Lutomirski, Andy" , "kernel-dev@igalia.com" , "kernel@gpiccoli.net" , "Yu, Fenghua" , Joshua Ashton , Paul Gofman , Pavel Machek , Pierre-Loup Griffais , Melissa Wen Subject: Re: [PATCH] x86/split_lock: Restore warn mode (and add a new one) to avoid userspace regression Message-ID: <20221006090418.GA14960@amd> References: <20220928142109.150263-1-gpiccoli@igalia.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="HlL+5n6rz5pIUxbD" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --HlL+5n6rz5pIUxbD Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed 2022-09-28 20:24:23, Luck, Tony wrote: > > So let's revamp the idea of having another option/mode for the split > > lock detector, which is hereby called "seq" (based on the original > > "sequential" naming in [0]). Also introduces a Kconfig option to give > > the option of Linux vendors have a choice what mode should be their > > default. While at it, fix/improve the documentation about bus locking. > > > > [1] https://github.com/doitsujin/dxvk/issues/2938 >=20 > Why not just use the workaround suggested in that bug report: >=20 > "so manual switching from default setting to split_lock_detect=3Doff h= elps as workaround here" >=20 > If you add this extra mode, I'm going to argue that the kernel default > should be "seq" rather than "warn". So these game players will need > to add a split_lock_detect=3Doff (or warn) option. Kernel should not cause userland regressions, and this is one. That should make it pretty clear what the solution is. And no, I don't like CONFIG option, either. Best regards, Pavel --=20 DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany --HlL+5n6rz5pIUxbD Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAmM+mhIACgkQMOfwapXb+vKLhACdH4DxQqgPIBpJlefnoth8wjtT uoIAmgONAilNmvaXGsTx6qaCB//qGcY/ =r8Et -----END PGP SIGNATURE----- --HlL+5n6rz5pIUxbD--