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 C3A1329CF0; Wed, 8 May 2024 11:43:59 +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=1715168641; cv=none; b=LavrtYvE3M9LO/Tmhd+7O4smTSRYGl0bk9OSx9L3z368rfMT9GS5/gPVVkHxOMjPQf4TDNfNNZbC0uCQH4hg+rt5Nv8NqL6WiFGehBMVGbzTevh/gVWm4sYjL9qvk0eb1TAreBtHh4IjKnv0ojLRvgBGG/l33UksNYuEwKy2cqU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715168641; c=relaxed/simple; bh=viXOb41qTU9kWx0jThG0vI6lZipWc8gTwUonH6gZKFE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=abziByhi3V7bafd9pgdr89FStoH8vYjr6yhCdelcx26hxxjUn9EtJMsC8X0MnC/TBlsR3CA2+ExvmdnPDIb5M4wG7+l3K5GN/Mn72r0GITlh/8cut7I2g7Y/vq4kY8Mxg6f5lx5/uwCmx0wCDrsjBOlFZPqQUlybhFuKaI3/jZ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=e+mJJGj4; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="e+mJJGj4" 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=M+v3H/nU/QJaIsBDguqkHxM6WbQlkmb4bw266jdl3Fc=; b=e+mJJGj4aLIe/+J6T8Hm4+D3wG dyPXbxOshBzcbT5w6a/ZDQtrLhtnu8pElcQqvUMeusU2QeTH4c833WnqnsYtpPrE1o5ZXqZOa6UPF CzJcW8TM9dGnylZOaJb9UFQ2CNQ5+LFWek8+83dctv2ea9YWy71nLx/Dbt16P3Ett8zqCGCmf17iL XbxvL+mYFlVuPDlI8e45hn27rDGgkQFLF2bsIErgyit3zD6BeGTKcxBiFKhO/5JmzYL04CfiuP7g+ 3KLIG97lILq3GUl0Fa5uwm6mf8KCvDt3P2odVsrHnpXuyiarOYl2EOHha8RgjN1oEM60BBMWNwPsc D/A2+QrA==; Received: from hch by bombadil.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1s4fiE-0000000FJie-2SkA; Wed, 08 May 2024 11:43:54 +0000 Date: Wed, 8 May 2024 04:43:54 -0700 From: Christoph Hellwig To: "Pankaj Raghav (Samsung)" Cc: Christoph Hellwig , hch@lst.de, willy@infradead.org, mcgrof@kernel.org, akpm@linux-foundation.org, brauner@kernel.org, chandan.babu@oracle.com, david@fromorbit.com, djwong@kernel.org, gost.dev@samsung.com, hare@suse.de, john.g.garry@oracle.com, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-xfs@vger.kernel.org, p.raghav@samsung.com, ritesh.list@gmail.com, ziy@nvidia.com Subject: Re: [RFC] iomap: use huge zero folio in iomap_dio_zero Message-ID: References: <20240503095353.3798063-8-mcgrof@kernel.org> <20240507145811.52987-1-kernel@pankajraghav.com> <20240508113949.pwyeavrc2rrwsxw2@quentin> 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: <20240508113949.pwyeavrc2rrwsxw2@quentin> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, May 08, 2024 at 11:39:49AM +0000, Pankaj Raghav (Samsung) wrote: > At the moment, we can get a reference to the huge zero folio only through > the mm interface. > > Even if change the lower level interface to return THP, it can still fail > at the mount time and we will need the fallback right? Well, that's why I suggest doing it at mount time. Asking for it deep down in the write code is certainly going to be a bit problematic.