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 45508C6FA8D for ; Tue, 6 Sep 2022 07:22:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 911528025B; Tue, 6 Sep 2022 03:22:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8993680224; Tue, 6 Sep 2022 03:22:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 73A5E8025B; Tue, 6 Sep 2022 03:22:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 5E93180224 for ; Tue, 6 Sep 2022 03:22:16 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 1EAECA0951 for ; Tue, 6 Sep 2022 07:22:16 +0000 (UTC) X-FDA: 79880817072.24.0232225 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf26.hostedemail.com (Postfix) with ESMTP id E8EE514008C for ; Tue, 6 Sep 2022 07:22:13 +0000 (UTC) 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=EHkWMjiSw6sMSHyk1j8ZDqGlGyNnE9pNuM0MT92Hdqk=; b=sEDZ5UjlGn93jHjXSEkts3JDd6 FWZwllRmftVq6Bf3K9hrkiAayQf7kTE1lZmaT2SaA7oLv1PyExzyofzMNCgBS1C2Z6rsSugqADthJ 7VpRieGXMNQBFDYEnXqb/VWQL8U1iFVztWKLDvSycJb+MN3aGWOLjHyONWzFsW2SIoopERqYNVAUX lbagcl6lzY277wvyHs4mJwfxbv8/uEpjjD66JSj5xWw4zoBWDRleTqK2DHTB+/wJ0mbEDX/vP87mF DyzJnia5+03A6jPHKeKFvBiC10WJBwHgsJmzrg2wwv4DfNCJPQ1iDBZ7izyurOhu0WggtuqNHjI5o cfTLMbDA==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVSuG-00Akwx-OK; Tue, 06 Sep 2022 07:22:00 +0000 Date: Tue, 6 Sep 2022 00:22:00 -0700 From: Christoph Hellwig To: John Hubbard Cc: Christoph Hellwig , Andrew Morton , Jens Axboe , Alexander Viro , Miklos Szeredi , "Darrick J . Wong" , Trond Myklebust , Anna Schumaker , Jan Kara , David Hildenbrand , Logan Gunthorpe , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, LKML Subject: Re: [PATCH v2 0/7] convert most filesystems to pin_user_pages_fast() Message-ID: References: <20220831041843.973026-1-jhubbard@nvidia.com> <50d1d649-cb41-3031-c459-bbd38295c619@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50d1d649-cb41-3031-c459-bbd38295c619@nvidia.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662448935; a=rsa-sha256; cv=none; b=lpEnpnvnd5idMrrEzl5FVj6otBFaFo5+GACfBurVevS86+ftzAKY0XlTlpIAeKpN4zPDn6 Wms2BHrEbqPyEs3kFmjOMlRlxFRerlEv/IywA0OHoB/W27VKBsBl//BkAyFPe8qp467vHT MpX5jRsQSRtZh0Y5WTZ9+SGXSI8IgoQ= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=sEDZ5Ujl; spf=none (imf26.hostedemail.com: domain of BATV+3c9dadc9e27e1b9c7a6f+6953+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+3c9dadc9e27e1b9c7a6f+6953+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=1662448935; 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=EHkWMjiSw6sMSHyk1j8ZDqGlGyNnE9pNuM0MT92Hdqk=; b=d3dRwaFLntRZTKhcyq6PY1HhdPBlHUnXVUq7yjIJp5I0PXjB2GLYAL9wYGivXjOBR9eSew c56Jl9pjrTd2T6vMR0xevy2hg8A8Gjr/5LPBrPwDmqQ2fUbl0Esc+XRMFYwpO8gTjaF2IV 8OhAirvOehJitDrh8AJ+oz+DQsuxZg8= X-Stat-Signature: 85igxxigzhauntjrnqs5wqe15gzde9ba X-Rspamd-Queue-Id: E8EE514008C Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=sEDZ5Ujl; spf=none (imf26.hostedemail.com: domain of BATV+3c9dadc9e27e1b9c7a6f+6953+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+3c9dadc9e27e1b9c7a6f+6953+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam03 X-HE-Tag: 1662448933-627663 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Sep 06, 2022 at 12:10:54AM -0700, John Hubbard wrote: > I would be delighted if that were somehow possible. Every time I think > it's possible, it has fallen apart. The fact that bio_release_pages() > will need to switch over from put_page() to unpin_user_page(), combined > with the fact that there are a lot of callers that submit bios, has > led me to the current approach. We can (temporarily) pass the gup flag to bio_release_pages or even better add a new bio_unpin_pages helper that undoes the pin side. That is: don't try to reuse the old APIs, but ad new ones, just like we do on the lower layers.