From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 418F53B583E; Thu, 9 Apr 2026 14:21:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775744508; cv=none; b=L43WjcLfSUrTuEd2rOBvQ8mjNcRLOV4QCAcIt6Nf0Jk8c3SxVek6rbnJMNO0KpSWwew5jz0CdR3e3u5I0uhai1N/kKO8nHQ4rPO12FONirvtFxLbtQrXe6nPMqAUSpWM7x2mMHm0dMKasBhbB1LB+UfYeQpetpKaZKGIosFEpPI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775744508; c=relaxed/simple; bh=KdI0AAIKXXq/sviYn1Y35plnhBxX8MDqftaLPVtTFvQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OAlqeiUxbBMCVuG1ZEngyVhS+iTa79BPOz+WNiiojt+b6FE1GytYtCOaKb35Uvl9jDJiRPFzr9yUjNocBdcRRYjKSCiVkgNJDGR9bFHCu5M8U1jE/wlm1H7MnQfpcFYeW3/xny2ans3DzKJwcAqEE046hygWmmcuvDelKcd9HGg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=oekmWysY; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="oekmWysY" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=AXd7Pgrw236phRDb4BUy2CY5/uYF1kqf7t0zPf4iggE=; b=oekmWysY0YtMv6PRwb3tb7EfZ5 FPdgB9Ion+gg5IECBzJHFaETbhF8z/KXCsS19UFElbUYttxXwl1T+y7bO7fPby4sniGIAVz9uSqg5 c4mFdGpGQ+tntp+RUbQVhaRCaCxQpQTO+my4kDbEUMVHmTc+v7VSiJWvji0wqfm+s0iMP3HQsdvYZ Xo0AXa6nOnf5nUqvpTf9KqQYeFDP7IsYTmfJb9UY3dgxJzdN6FNk7B7g+4aOm+VG4kMcqfSTZzPqU /+Cv5Ch7yl1d1LRsdbwsPhZHDnGV2UqjB/9MqBOFQ56ukeTyWu7rAHLv/oTFES9Ni7BPzMC/Ti7bN p/jcoRfg==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1wAqG2-0000000AgGR-2cnH; Thu, 09 Apr 2026 14:21:22 +0000 Date: Thu, 9 Apr 2026 07:21:22 -0700 From: Christoph Hellwig To: Jan Kara Cc: Christoph Hellwig , Jeff Layton , Alexander Viro , Christian Brauner , "Matthew Wilcox (Oracle)" , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Mike Snitzer , Jens Axboe , Chuck Lever , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v2 1/3] mm: kick writeback flusher instead of inline flush for IOCB_DONTCACHE Message-ID: References: <20260408-dontcache-v2-0-948dec1e756b@kernel.org> <20260408-dontcache-v2-1-948dec1e756b@kernel.org> 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: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Thu, Apr 09, 2026 at 09:21:36AM +0200, Jan Kara wrote: > > So I think you'll want a new WB_start_dontcache bit, a new > > get_nr_dontcache_pages() helper on a new node counter, etc. > > But I'm not sure how you imagine this would work without restricting > writeback to particular inodes. Maybe we could mark inodes which have > folios with dropbehind set and make flush worker only write such inodes? I'd only expedite writing by the number of pending dontcache folios. It would still write the least recently dirtied inodes.