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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E9D1BC83F27 for ; Wed, 16 Jul 2025 11:32:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0801610E276; Wed, 16 Jul 2025 11:32:51 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; secure) header.d=mailbox.org header.i=@mailbox.org header.b="QlRIecdT"; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="fPHbkzVj"; dkim-atps=neutral Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171]) by gabe.freedesktop.org (Postfix) with ESMTPS id 30B8C10E276 for ; Wed, 16 Jul 2025 11:32:50 +0000 (UTC) Received: from smtp1.mailbox.org (smtp1.mailbox.org [IPv6:2001:67c:2050:b231:465::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4bhv745ktbz9sm3; Wed, 16 Jul 2025 13:32:48 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1752665568; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PMGfdoOoS6iQPCr/bywDVwi8zs4P0HQGhorIHlY9F0Y=; b=QlRIecdT2zomfbh9oE58e8hlTADUyLSGA5KBsGXFhFxZ2gJVyohWo+wjMqEAKUWuBIpbuy AVXZlQ+MF4gFfGrDr5huVjmUQI2EvVku8ydU/J4rzovLCQ+Eujx7RJWFxJJsZR/EjjBbL0 3Z9WVTLAAqVyR6xTmJ+GiB7TrJAmIQCPCfOtEcanqeWY6g84GDpCytppOJOaiXkq/YVNIH KH+KsnpJnc3kE/Kqri3ADs2F12yHBT5rUMewWknodtweizyVjYMjUjkI37KG0cMexuzAuD xxnrZjgv6GP28QA0SIwVRhOnP48BFTbdqNn4hnu6TyQchdmtp2cdhEJrTKRfrg== Authentication-Results: outgoing_mbo_mout; dkim=pass header.d=mailbox.org header.s=mail20150812 header.b=fPHbkzVj; spf=pass (outgoing_mbo_mout: domain of phasta@mailbox.org designates 2001:67c:2050:b231:465::1 as permitted sender) smtp.mailfrom=phasta@mailbox.org Message-ID: <0e58a96e61054ae88de112cb8be7e45e2b6f4f0c.camel@mailbox.org> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1752665566; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PMGfdoOoS6iQPCr/bywDVwi8zs4P0HQGhorIHlY9F0Y=; b=fPHbkzVjDz1UnCrUjS+ABf7uUQCb09yoiyiqZmhcYhqyHArLVUWMZlvE4DzGTmd7jHxzTd xwucBFJh4lxed7tnPztrO5ZCy3AoZcFpGjZIHkqiF4KRcaeSoVo0+P/q24VHe0sKdlibdC fZpl0v15FIq0r/m1Tikqj4qXRQsIdjjwipOMrkNJUtPcH8WldUzPwSIcppUZ9DO7DpmQ+u PLBrMzSDEZSZ41MO/yMi3Urs/bBjdiS5/dC04LqRvoe60ja+znvbV+q9lJFYXLMh05SPbw mx9MlGfNlIiOCXiZqjXkK9TvzajgulFW9pc7DsZewdWmmmVhhGnQwMVdAUO0hg== Subject: Re: [PATCH] drm/sched: Remove optimization that causes hang when killing dependent jobs From: Philipp Stanner To: Greg Kroah-Hartman , Christian =?ISO-8859-1?Q?K=F6nig?= Cc: phasta@kernel.org, Michel =?ISO-8859-1?Q?D=E4nzer?= , "cao, lin" , "dri-devel@lists.freedesktop.org" , "Yin, ZhenGuo (Chris)" , "Deng, Emily" , "dakr@kernel.org" , "matthew.brost@intel.com" , Sasha Levin Date: Wed, 16 Jul 2025 13:32:42 +0200 In-Reply-To: <2025071635-petition-unhitched-bdd0@gregkh> References: <20250715135033.706126-1-lincao12@amd.com> <49d822fc0f46e0fdeaccaeb2fbb1ade1c5cb1e5d.camel@mailbox.org> <2025071635-petition-unhitched-bdd0@gregkh> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MBO-RS-ID: 758d3edeb2c9d6dc96d X-MBO-RS-META: pf8mu6ehkws4qaansn1j83h9m9mryx1f X-Rspamd-Queue-Id: 4bhv745ktbz9sm3 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: phasta@kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, 2025-07-16 at 13:15 +0200, Greg Kroah-Hartman wrote: > On Wed, Jul 16, 2025 at 12:58:28PM +0200, Christian K=C3=B6nig wrote: > > On 16.07.25 12:46, Philipp Stanner wrote: > > > +Cc Greg, Sasha > > >=20 > > > On Wed, 2025-07-16 at 12:40 +0200, Michel D=C3=A4nzer wrote: > > > > On 16.07.25 11:57, Philipp Stanner wrote: > > > > > On Wed, 2025-07-16 at 09:43 +0000, cao, lin wrote: > > > > > >=20 > > > > > > Hi Philipp, > > > > > >=20 > > > > > >=20 > > > > > > Thank you for the review. I found that this optimization > > > > > > was > > > > > > introduced 9 years ago in commit > > > > > > 777dbd458c89d4ca74a659f85ffb5bc817f29a35 ("drm/amdgpu: drop > > > > > > a > > > > > > dummy > > > > > > wakeup scheduler"). > > > > > >=20 > > > > > >=20 > > > > > > Given that the=C2=A0codebase has undergone significant changes > > > > > > over > > > > > > these > > > > > > 9 years. May I ask if I still need to include the Fixes: > > > > > > tag? > > > > >=20 > > > > > Yes. It's a helpful marker to see where the problem comes > > > > > from, and > > > > > it > > > > > adds redundancy helping the stable-kernel maintainers in > > > > > figuring > > > > > out > > > > > to which kernels to backport it to. > > > > >=20 > > > > > If stable can't apply a patch to a very old stable kernel > > > > > because > > > > > the > > > > > code base changed too much, they'll ping us and we might > > > > > provide a > > > > > dedicated fix. > > > > >=20 > > > > > So like that: > > > > >=20 > > > > > Cc: stable@vger.kernel.org=C2=A0# v4.6+ > > > > > Fixes: 777dbd458c89 ("drm/amdgpu: drop a dummy wakeup > > > > > scheduler") > > > >=20 > > > > FWIW, Fixes: alone is enough for getting backported to stable > > > > branches, Cc: stable is redundant with it. > > >=20 > > > Both are used all the time together, though. And the official > > > documentation does not list dropping Cc: stable as a valid option > > > in > > > this regard > > >=20 > > > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.ht= ml#option-1 > > >=20 > > >=20 > > > As long as the official documentation demands it, I'm not willing > > > to > > > drop it. If the docu were to be changed, that would be fine by > > > me, too. > >=20 > > As far as I understand "CC: stable" and "Fixes:" tags are to handle > > two distinct use cases. >=20 > Yes. >=20 > > "CC: stable..." means please backport, eventually with a kernel > > version and/or necessary pre-requisites. >=20 > Yes. >=20 > > "Fixes:" only backport if you have this patch in your tree as well. > > In other words it is a restriction when to backport something. >=20 > No. >=20 > "Fixes:" is only for you to say "this commit fixes this other > commit". > And when you add a cc: stable, that will get you a FAILED email if > the > commit does NOT apply that far back. Does that mean we should NOT add Fixes: if the fixing patch does not apply on top of that old commit? And if so, should we drop the Fixes: tag completely in such cases as Lin suggested in this thread? P. >=20 > "Fixes:" on its own does NOT mean it will ever be backported to the > stable trees.=C2=A0 But because so many people KEEP GETTING THIS WRONG > (despite cc: stable@ happening first in history _before_ Fixes: came > about), we do try to sweep the tree every so often and do a "best > effort" backport of those only marked with Fixes: >=20 > But that happens later, if at all, and you do NOT get a FAILED email > if > a patch does not apply to a stable branch. >=20 > So ALWAYS use cc: stable@ for something you want backported to stable > kernels.=C2=A0 That's what the documentation states, and is what we have > been > doing for 15+ years now (is it 20?). >=20 > thanks, >=20 > greg k-h