From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171]) (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 B1E8233893D; Wed, 11 Feb 2026 10:09:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770804549; cv=none; b=DW0YcGI7EO4c9aNv8SCoJb/Yn8KWv/GFaoWe6smapazkpC891p9uqJIqes0JTTEoywb5ed0eOJPY2eyFWSCAHMc2vnr9Hqb8ZAJbRwQWhRW5Nh50Wu2pGq6G2RMPSuLhPRklbuTcAC+M42uo8XN2nqDxYkuQlULm/EgZtQ9gcjk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770804549; c=relaxed/simple; bh=HEVCh6pKz/bnqK7JQNj4OgLdAcyirEtwdMFUXxgeC/o=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=oQQ/BQJ+4O9dC0jXCnIFUaP3HQQwB3e6+t6aEIcvAMK4ejISMwepHDmx11EyxmeDlCyRblbx3aYUrQbL5Jg7STwn0bQE+MfQgQ3jJab6tcNKZUR7DTgZh+3pQxHs2oq7F5LMpkTNOpgIEzakyLzvAwZMIVdYIqvqu/0WTi9lQig= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=tRtKIc0H; arc=none smtp.client-ip=80.241.56.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="tRtKIc0H" Received: from smtp102.mailbox.org (smtp102.mailbox.org [IPv6:2001:67c:2050:b231:465::102]) (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 4f9vKV3Yjpz9sQX; Wed, 11 Feb 2026 11:09:02 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1770804542; 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=HEVCh6pKz/bnqK7JQNj4OgLdAcyirEtwdMFUXxgeC/o=; b=tRtKIc0Hcxxsd+KjoFbsOzU51z2hp7ajQRuUokDGudMBL97qarHV46d+zB4dAX7vLB0/my KCiOSIr0Nt1SyYi72myoR82iFnvqSwz/WTOjsh/ofhCIwn/EJ3EcVSd+rSQ38fFXF6T4WQ LY89rlr3SBw6HTwuIlhCh60xwHAJJ81o9Vvo28q5WhzdrhZSNfLCTZks3G2qJOjoCzlf6J 8CM11lgCwmDroSLsgXHgSiR+N/eB4yNFrD/U6fs6kyRYIgZRkrmibPvSM/3wyLaTH22ATl ZM8/+8OV3I42aSh9Z2x6g/HUd2QExL5fYF3MvY4FTcVZ2DBatX6KnJ+dhwslKQ== Message-ID: <5f777c33469ef5c34467a12609233d72064a9297.camel@mailbox.org> Subject: Re: [RFC PATCH 2/4] rust: sync: Add dma_fence abstractions From: Philipp Stanner Reply-To: phasta@kernel.org To: Danilo Krummrich , Alice Ryhl Cc: Christian =?ISO-8859-1?Q?K=F6nig?= , Boris Brezillon , phasta@kernel.org, David Airlie , Simona Vetter , Gary Guo , Benno Lossin , Daniel Almeida , Joel Fernandes , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, rust-for-linux@vger.kernel.org, lucas.demarchi@intel.com, thomas.hellstrom@linux.intel.com, rodrigo.vivi@intel.com Date: Wed, 11 Feb 2026 11:08:55 +0100 In-Reply-To: References: <20260205095727.4c3e2941@fedora> <20260209155843.725dcfe1@fedora> <20260210101525.7fb85f25@fedora> <4e84306c-5cec-4048-a7eb-a364788baa89@amd.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MBO-RS-META: ehiawnajzhr1fnkrdkutyo7fb9kaidn4 X-MBO-RS-ID: 96200e600e59c8d4974 On Wed, 2026-02-11 at 10:57 +0100, Danilo Krummrich wrote: > (Cc: Xe maintainers) >=20 > On Tue Feb 10, 2026 at 12:40 PM CET, Alice Ryhl wrote: > > On Tue, Feb 10, 2026 at 11:46:44AM +0100, Christian K=C3=B6nig wrote: > > > On 2/10/26 11:36, Danilo Krummrich wrote: > > > > On Tue Feb 10, 2026 at 11:15 AM CET, Alice Ryhl wrote: > > > > >=20 [=E2=80=A6] > > > >=20 > > > > Or in other words, there must be no more than wq->max_active - 1 wo= rks that > > > > execute code violating the DMA fence signalling rules. > >=20 > > Ouch, is that really the best way to do that? Why not two workqueues? >=20 > Most drivers making use of this re-use the same workqueue for multiple GP= U > scheduler instances in firmware scheduling mode (i.e. 1:1 relationship be= tween > scheduler and entity). This is equivalent to the JobQ use-case. >=20 > Note that we will have one JobQ instance per userspace queue, so sharing = the > workqueue between JobQ instances can make sense. Why, what for? P.