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 7C4DBCCD1A5 for ; Tue, 21 Oct 2025 23:28:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3DCE310E35D; Tue, 21 Oct 2025 23:28:35 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="KFtLUaQM"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6E2B210E058; Tue, 21 Oct 2025 23:28:33 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 8DB4860489; Tue, 21 Oct 2025 23:28:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1108BC4CEF1; Tue, 21 Oct 2025 23:28:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761089312; bh=yLUPTfQ0fOP6q5PaV+LDloE5TD4E7DwDV7LaIqrcPSg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KFtLUaQMOWo3d76/lTJ9Tect9Ec+1Rgy0s5sznhblE6CqzqeBEEIkhVn2yHdYo0Ye 7RiFzJnGfcKEy2irBmH4lmtIo6ZTMztgNrnilGQoqgJlzYeaztDVweFbYsdvqxHXHs dgq40r4UMHBDGpZ0xefp3NhkcewNtcPqTQLuotkaYql2T23nUk9xZ3iOpooeeUo7bh qhhhOsf0ezVALtKc2JkPRjcqV6MPyXkwTSf3aiYqGmmiGsfTrVLXYMBJwMq18Z2qLB S6dpeoaHd3cSkvXjWxJPoJmMQc5TcolvDGooBsOuBg7G5iN9ZDtbCOnhSp4VBYrjqZ IbWawI7Hk9f4g== Date: Tue, 21 Oct 2025 13:28:31 -1000 From: Tejun Heo To: Matthew Brost Cc: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, jiangshanlai@gmail.com, simona.vetter@ffwll.ch, christian.koenig@amd.com, pstanner@redhat.com, dakr@kernel.org Subject: Re: [RFC PATCH 1/3] workqueue: Add an interface to taint workqueue lockdep with reclaim Message-ID: References: <20251021213952.746900-1-matthew.brost@intel.com> <20251021213952.746900-2-matthew.brost@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" Hello, On Tue, Oct 21, 2025 at 03:04:14PM -0700, Matthew Brost wrote: > > Hmm... would it make sense to tie this to WQ_MEM_RECLAIM - ie. enable it > > implicitly on workqueues w/ the flag set? > > I had considered this, and for a while I thought WQ_MEM_RECLAIM already > did what I'm suggesting—especially since I’ve spotted bugs in drivers > where I would have expected lockdep to catch them. > > In my opinion, this approach is better, but it has a broader kernel-wide > scope and could potentially break some things. My subsequent patches > will likely break one or two DRM drivers, so it might not be a concern > to fix everything that breaks across the kernel. It's up to you which > route we want to take here. Yeah, it is bothersome that WQ_MEM_RECLAIM doesn't currently have a way to ensure compliance. I just didn't know about the lockdep mechanism. Can you please update the patch so that WQ_MEM_RECLAIM implicitly enables the checking? Thanks. -- tejun