From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01051C04FFE for ; Wed, 8 May 2024 11:44:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 884E56B016E; Wed, 8 May 2024 07:44:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 835A86B016F; Wed, 8 May 2024 07:44:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 724286B0170; Wed, 8 May 2024 07:44:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 5599B6B016E for ; Wed, 8 May 2024 07:44:02 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 17321141066 for ; Wed, 8 May 2024 11:44:02 +0000 (UTC) X-FDA: 82095044724.04.A43EB4F Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf25.hostedemail.com (Postfix) with ESMTP id 778DDA0007 for ; Wed, 8 May 2024 11:44:00 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=e+mJJGj4; spf=none (imf25.hostedemail.com: domain of BATV+51ef0b7171324ca53c39+7563+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+51ef0b7171324ca53c39+7563+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1715168640; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=M+v3H/nU/QJaIsBDguqkHxM6WbQlkmb4bw266jdl3Fc=; b=CuZy/EzWYAV1OU4HYrf27YbyaYo7vXG0T3mL51dPobDikP+PkdSc4muKnWG2BhQAO/A+n+ dFbbfU9izf6DWWH7jbvQvCbgPpkLlsw2TG/dMr4C72yYdp+rgp5QklI/+evo4dNoKWbBGR KbuBHdpp9Z7z6iKolD9AI8PfXejZ9iM= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=e+mJJGj4; spf=none (imf25.hostedemail.com: domain of BATV+51ef0b7171324ca53c39+7563+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+51ef0b7171324ca53c39+7563+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1715168640; a=rsa-sha256; cv=none; b=ZtiJWwji1CvPUIvvhYqvkoj+UsQDTcwEMtyGzcDiq3m2ndCW/KtH7Cq+QkbGNvGTEjQmed eozraKGJJ0gbj11qT287EOyoQisGilK7Z2D77DnHp2JTX4tQpp9G06P7m7QSf/jUG4lyhO 2lubcTs0uiuet8BtEDv2aI91v1r6nOw= 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> 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 X-Rspam-User: X-Rspamd-Queue-Id: 778DDA0007 X-Rspamd-Server: rspam06 X-Stat-Signature: scf9iz5gtwo754j99gorcuumquacp5fi X-HE-Tag: 1715168640-325503 X-HE-Meta: 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 TOxMCXc5 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000003, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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.