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 373D2140E4F; Wed, 27 May 2026 06:31:59 +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=1779863520; cv=none; b=iXWJnauMmTKFqgfV9An6Hx4yvMoCmaaCk64SNOUhrCVkh1diKhWpF9uuPFv0rj7UEA25ZfhN4xW9FRrx0Ns7gcCZNrEj3USJagXBgkoLSrVNuNUUA+tXYl/kkPB8iQA1Gbylc4aNVz8Uf3cS3aSjrXN7vYf2LU6LK5ALwWx6/Wg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779863520; c=relaxed/simple; bh=f4uf+8uNOy9gjTRC+xUpy219vU0iEBItjTCMIrroVeM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=O8Xxve2V8f4jAjZMWAQTbY5XRqsBpLl00UjMBLoOPmQdfrEPx6PihrGwkAhO8cj1MKvvM1miIxmidn+yJkwUoog12yyS1tPjuAvOUJpVLcWKoz7eLdA8B7SClue23RLLliYAkY2z7z7rp7VsLuV+JmDrSfNTqd8rnppDuLTx5iI= 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=NUzqHve8; 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="NUzqHve8" 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=nWhD6NqGWQeaAF9weLMiDIdx5fT308tj+4gRK0S0CiQ=; b=NUzqHve8UC+23s3rUSjCC3Rq5Z KvOYLnH5KIouDOlaogy7L0fmNrUmy3yijttvpBzJWa34SwE6Ts5eOS5uZ1zQ1kwMkiH0FCTME1B5v 343TQK3949E+T+zXA3en4J0yTTU2Y5tU6fB5QuMbUJd/5ETZzIpFVCEHjbHjZalxiwm0udRHofEPu JoJ9lz+Twd7M0Ycq+jimrec5bxUKNGPtkxkW4SYh78xE5r/tNgL3P1R+4wRRh5mkSL2rn9+oLSsUi pm7o2iyAxQC9R6MV1khw1ig6MyNgg3P6JHfeaFj5IfJeeQlXPWtEWzFdtFA8ygTTVW300stpZHCo6 RoL2an7g==; Received: from hch by bombadil.infradead.org with local (Exim 4.99.1 #2 (Red Hat Linux)) id 1wS7o6-00000003PEM-0j4G; Wed, 27 May 2026 06:31:58 +0000 Date: Tue, 26 May 2026 23:31:58 -0700 From: Christoph Hellwig To: Theodore Tso Cc: Jaegeuk Kim , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Matthew Wilcox , linux-f2fs-devel@lists.sourceforge.net, Christoph Hellwig , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Akilesh Kailash , Christian Brauner Subject: Re: [f2fs-dev] [PATCH v2] f2fs: another way to set large folio by remembering inode number Message-ID: References: <20260521155748.GA79343@macsyma-wired.lan> <20260522141115.GA8258@macsyma-wired.lan> <20260522224108.GA18663@macsyma-wired.lan> Precedence: bulk X-Mailing-List: linux-api@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 Tue, May 26, 2026 at 08:21:43PM -0500, Theodore Tso wrote: > The bottom line is if it's right after device boot, there are simple > techniques that don't require hacking up the f2fs. But in the > demand-loaded case, calling compact_memory() is the last thing you'll > want to do. You're better either asking the mm to allocate the 4k > pages, or do whatever compaction it can do to just free up 2GB worth > of folios. (Calling compact_memory() is overkill, and only makes > sense in the context of benchmark / proof of concept demo.) Or have a lot of clean pagecache using higher order folios that can you can instantly reclaim?