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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DFCE3C4743C for ; Wed, 23 Jun 2021 08:00:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8815F60FEE for ; Wed, 23 Jun 2021 08:00:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8815F60FEE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7BD7E8D0003; Wed, 23 Jun 2021 04:00:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 76DB88D0002; Wed, 23 Jun 2021 04:00:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 636D48D0003; Wed, 23 Jun 2021 04:00:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0177.hostedemail.com [216.40.44.177]) by kanga.kvack.org (Postfix) with ESMTP id 2C9808D0002 for ; Wed, 23 Jun 2021 04:00:01 -0400 (EDT) Received: from smtpin36.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 511CE82D35F0 for ; Wed, 23 Jun 2021 08:00:01 +0000 (UTC) X-FDA: 78284240202.36.CC4A882 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf05.hostedemail.com (Postfix) with ESMTP id C71B6E000113 for ; Wed, 23 Jun 2021 08:00:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=KMXVCqZ54Yxoe8fux+wICaoLLPpO0k0UUumj828rXPg=; b=SB9LAhJPa+YmbC+MVoju6lAnq4 EHw/aaGCDFZqwNd0m/MS2oBu6bYz2ycQ/pMYHn/IL2zXe4pJBL2SETILoAjb0iVu9Zue4MCp+ryhp t2rhWZkMjbObtMnwcnCmY/NBO1Y1iImPWzZutHOHet8mTNUmvWcFuR29M4Dx97yLQdzNAolYxuk7S T1ckVoPyivYwJEMwx/cPUFba/EePTSVXNIl1Q7h2oxSoWR3CHc/UObhrrnQHCALHxbGW5xSTKukAs APMFZm9prZER7OcDGKTWOlszETSy7Di/YFN/ihuIf9/lhdA62xm15VmS8jhfDa5LmK6ciFOpg/2/m h71SMpag==; Received: from [2001:4bb8:188:3e21:6594:49:139:2b3f] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1lvxmk-00FBQW-OW; Wed, 23 Jun 2021 07:59:09 +0000 Date: Wed, 23 Jun 2021 09:58:52 +0200 From: Christoph Hellwig To: "Matthew Wilcox (Oracle)" Cc: akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 03/46] mm: Add kmap_local_folio() Message-ID: References: <20210622121551.3398730-1-willy@infradead.org> <20210622121551.3398730-4-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210622121551.3398730-4-willy@infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: C71B6E000113 X-Stat-Signature: qgzh5ae14u85hury66ponp3zenwwkb8b Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=SB9LAhJP; dmarc=none; spf=none (imf05.hostedemail.com: domain of BATV@casper.srs.infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=BATV@casper.srs.infradead.org X-HE-Tag: 1624435200-899585 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, Jun 22, 2021 at 01:15:08PM +0100, Matthew Wilcox (Oracle) wrote: > This allows us to map a portion of a folio. Callers can only expect > to access up to the next page boundary. > > Signed-off-by: Matthew Wilcox (Oracle) This looks sensible to me: Reviewed-by: Christoph Hellwig While we're at it: flushing incoherent mappings for use with kmap has been a complete mess. I've been trying to fix this with kunmap_local_dirty, but that could use another review, as well as a folio version probably give that one prime use case of folios is to have them mapped into userspace.