From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(No client certificate requested)
	by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2604B3BB10F
	for <linux-kernel@vger.kernel.org>; Mon, 29 Jun 2026 12:09:34 +0000 (UTC)
Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18
ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;
	t=1782734976; cv=none; b=RwK0a8ckvs168UbnBGKm7Vb2n1ONZ2ac7oRHYPaIgWisGQKfZ1nJnxbJghHM57invkGCGNSbbEEfU9FLretx3sLKyuSoZlMvzHkikma6iRRTDfxmbW2ctJR2p1ID7E37kvX22Rw5rtX+8mDBRpUWkcVbyEAUEucSQ/YI3PfRNe4=
ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org;
	s=arc-20240116; t=1782734976; c=relaxed/simple;
	bh=XhAnqC/vUiB1NJ7PpfT3wHJZu6PfkNSLn9yo/qTjZQw=;
	h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From:
	 In-Reply-To:Content-Type; b=m68AC9hlJHs3K1z/uBdwW2wUc3lUZs1Asy7JjzG0UlETBBwMh4wN+MLE2MhRn9F0XemOOnxgX1eRHasWoJC0ycq8lGIkgTMkvcUHdI9wGcSkpINB0e+VQIDKgGV4UhyZiPNpX4bGAtUT0W6Nj+G8JhXgrOIlYeCXM/iE5eLPRVE=
ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oWOu9XeD; arc=none smtp.client-ip=100.103.45.18
Authentication-Results: smtp.subspace.kernel.org;
	dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oWOu9XeD"
Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A4571F000E9;
	Mon, 29 Jun 2026 12:09:32 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org;
	s=k20260515; t=1782734974;
	bh=gO7vksODGeA6boCayY1A9JuxqrUFKMw+C8sb90UNlR4=;
	h=Date:Subject:To:Cc:References:From:In-Reply-To;
	b=oWOu9XeDVQ+t70CtakGVe85lb/PYZj8EZ0nVxHUsudH8riLgsWTGW5slBK8YxG1IT
	 cLDlvJMBMx0unf7aSdhlDyrzOnid365JQCgqYNY+tIF2V4CCj+59Wqb8dyoRUgCeex
	 ud26FgFvxVcbUAS/NaMo0/FrXcpB/ElWZzme1eeLtHXhNiudHAT2bVzBdNgE7kmat8
	 bprqA5FulgYfeIp2Pafa8D1NzyKuPWRyuknilFThFPBpAPXtM/JnFprprLGKlPg5Ot
	 1RjfeJUvosElCKxgI5fDaXV/qKGRZ2bno9lIHRekpMAyEPP1twH3nc6KnK0ZXpVi0/
	 ekI2vZQtgue1g==
Message-ID: <5ed4ecfe-05bb-4bdd-9aa3-155e1d926861@kernel.org>
Date: Mon, 29 Jun 2026 14:09:30 +0200
Precedence: bulk
X-Mailing-List: linux-kernel@vger.kernel.org
List-Id: <linux-kernel.vger.kernel.org>
List-Subscribe: <mailto:linux-kernel+subscribe@vger.kernel.org>
List-Unsubscribe: <mailto:linux-kernel+unsubscribe@vger.kernel.org>
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 1/2] drm/sched: Guard sched->ready with ACCESS_ONCE()
To: Philipp Stanner <phasta@kernel.org>
Cc: Matthew Brost <matthew.brost@intel.com>,
 =?UTF-8?Q?Christian_K=C3=B6nig?= <ckoenig.leichtzumerken@gmail.com>,
 Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
 Maxime Ripard <mripard@kernel.org>, Thomas Zimmermann <tzimmermann@suse.de>,
 David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
 dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <20260629104040.2695163-2-phasta@kernel.org>
From: Danilo Krummrich <dakr@kernel.org>
Content-Language: en-US
In-Reply-To: <20260629104040.2695163-2-phasta@kernel.org>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit

> +	WRITE_ONCE(sched->ready, false);

Don't we need smp_store_release() here and

> +	return READ_ONCE(sched->ready);
smp_load_acquire() here?

Also, what about drm_sched_init()? It also seems that this is accessed from
amdgpu without the drm_sched_wqueue_ready() helper about a million times. :)

	$ grep -Rin "sched\.ready" drivers/gpu/drm/amd | wc
	$     119     544   10320

There may be false positives, but from a quick glance at least most of them seem
to actually come from the scheduler.