From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 16B712D6E40; Mon, 11 Aug 2025 17:51:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754934689; cv=none; b=V8QjgMQCi+WaRpQg4lZWSh/Nipl82NQgZs1gApBy5cI6b7vZsoJolW4VhXrvBuO84OxRb6VIYXrsYPakG+8iSZIWiS+upsDSzc2EUgpeIA9oGAb9DLtEtpCWINlByac2/pdpuEFpVjzDRavG2as1KSCqJjui6QfqR/g6tPmTWz8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754934689; c=relaxed/simple; bh=jUDKUC55/ByDGIJqIA62x2PDfSmedYhIlXa/WxG9+xY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cg9rleOXpEyLOXRF+snb27mdVLNPLlHL6h+wc6FTHFbN2jW1Jwwtr5Q1Swjca7j7BGQPxkOGwjAHfY/uCpW+KX4hTtHX9KT5/w/sU/ewUTqhY/iurIHDYNhDsHd+VtYswdKmjYFHWA2kV15zxRnxX2qwSqIP5rTLfXYfmfVR5mw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RwDDFWEn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RwDDFWEn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75DD5C4CEED; Mon, 11 Aug 2025 17:51:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754934688; bh=jUDKUC55/ByDGIJqIA62x2PDfSmedYhIlXa/WxG9+xY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RwDDFWEnS36tkphynxs54ndKSNk+KE+GFn6j1hqfG6LyxFneYRU8YKmlxC1aCOexj +J+4DodytZelYW+7LpRQt2Ze9RHQardqYU3+MrD+lP1V+R1lZdVVgtBgNVoKWwVO+k FhLvmOQ8lyZtW2Qpf3fwaNa64pzAXgeO9mCBf5OGpjCmpNr+vilZPwkaF0DcnqQ3Rf gRH1CffV0vn69F/RrvV0auCZTWX1BT2PfXWqDFXVkqNSIpb4iqeDw1QlxI89uR1/ol ixBn86Wy1b8PUcN2NGuSN+qcwDp4mAIqkBbI4ZcCA1cksE8+9hScjxXhPMjX8ZdZMQ o0VDL6XwunyUw== Date: Mon, 11 Aug 2025 07:51:27 -1000 From: Tejun Heo To: Christoph Hellwig Cc: Andrey Albershteyn , fsverity@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, david@fromorbit.com, djwong@kernel.org, ebiggers@kernel.org, Lai Jiangshan , linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC 04/29] fsverity: add per-sb workqueue for post read processing Message-ID: References: <20250728-fsverity-v1-0-9e5443af0e34@kernel.org> <20250728-fsverity-v1-4-9e5443af0e34@kernel.org> <20250811114519.GA8969@lst.de> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250811114519.GA8969@lst.de> Hello, On Mon, Aug 11, 2025 at 01:45:19PM +0200, Christoph Hellwig wrote: > On Mon, Jul 28, 2025 at 10:30:08PM +0200, Andrey Albershteyn wrote: > > From: Andrey Albershteyn > > > > For XFS, fsverity's global workqueue is not really suitable due to: > > > > 1. High priority workqueues are used within XFS to ensure that data > > IO completion cannot stall processing of journal IO completions. > > Hence using a WQ_HIGHPRI workqueue directly in the user data IO > > path is a potential filesystem livelock/deadlock vector. > > Do they? I though the whole point of WQ_HIGHPRI was that they'd > have separate rescue workers to avoid any global pool effects. HIGHPRI and MEM_RECLAIM are orthogonal. HIGHPRI makes the workqueue use worker pools with high priority, so all work items would execute at MIN_NICE (-20). Hmm... actually, rescuer doesn't set priority according to the workqueue's, which seems buggy. Thanks. -- tejun