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 3ED181DDC33; Mon, 15 Dec 2025 06:59:14 +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=1765781957; cv=none; b=jYP+uNe1thCE7utZYiYeIhT74kzmWeOfWcmJTOB2zq13RciqjfQCnRufs0uIT8N6L/rmakOVCR70pZRmYmNMYajlgdfIPHzDkxQjTrDRvLRtu5Rhx+txGPQOA/eppectvjwkn2R3g4++5PUObi+n9hDz82NY0gvcrHkYHlbcf44= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765781957; c=relaxed/simple; bh=pftUfUULzPZ9GsBY/fjgHAq8AvUe5Ys25wSUqJUcki0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Fc7AGeG1Tw69RlWihh8ybhYWYQAycRr6Q6LoJv/4krOzgd/VTPQjv3FdEtxqj0EW39r1rhuEo84rhLbjbSuhUCt3j2IvUGlAwVscGLxXADd4OJbpgQMhWEdStDRgVrqNJrZPuLDLF8a7mkNzYtzzlYv0PwfAoO5gC6eB61EYALE= 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=4BSHxxje; 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="4BSHxxje" 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=vwJMnZv4O2KS7JbGg+hlCsT0qlO0aGhYisR4zAG21iE=; b=4BSHxxjevVg68YdWTxLIftGPsI +MtOLp/rV2x4zbcffQzZlIR1ecP/uUvPeieNIix7+kkuPW5UdfBdrxJtK3YGVYgMF9hZ+k8w05CEg AtGtdAbOxSBhxd2XhlauoGfES+Itb7wcQ36hZ6QC8NH4iKfuCn/qksV99tx6DSiRwCJBd1Jt+nEn9 603+ZF3ed2zGOr8udl5BIACij1QDa+MCX8THUpSHI6m0oYKu4zAe99nuRQcNykW9zpyagojcmt1Rh P33ssYJ88Q3BNwt0zcQX7oFA4lmOjaXdhMDcOrQdmyNogdVZOlgFGjsonwSeqGWS9QQxzXpsiOhor R6VCv9jw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vV2Y3-00000003Az8-2YW5; Mon, 15 Dec 2025 06:59:11 +0000 Date: Sun, 14 Dec 2025 22:59:11 -0800 From: Christoph Hellwig To: Johannes Weiner , Jens Axboe Cc: Deepanshu Kartikey , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Subject: retiring laptop_mode? was Re: [PATCH] mm: vmscan: always allow writeback during memcg reclaim Message-ID: References: <20251213083639.364539-1-kartikey406@gmail.com> <20251215041200.GB905277@cmpxchg.org> Precedence: bulk X-Mailing-List: linux-kernel@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: <20251215041200.GB905277@cmpxchg.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Sun, Dec 14, 2025 at 11:12:00PM -0500, Johannes Weiner wrote: > That reasoning doesn't make sense to me. Reclaim is always in response > to an allocation need. The laptop_mode idea applies to cgroup reclaim > as much as any other reclaim. > > Now obviously all of this is pretty dated. Reclaim doesn't do > filesystem writes anymore, and I'm not sure there are a whole lot of > laptops with rotational drives left, either. Also I doubt anybody is > still using zone_reclaim_mode (which is where the may_unmap is from). Yeah. I wonder if we should retire laptop_mode. It was a cute hack back then, but it has it's ugly fingers in way to many places and should be mostly obsolete by how writeback works these days.