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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 93D86C4743C for ; Wed, 23 Jun 2021 08:00:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FC09611C1 for ; Wed, 23 Jun 2021 08:00:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230082AbhFWICX (ORCPT ); Wed, 23 Jun 2021 04:02:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229902AbhFWICP (ORCPT ); Wed, 23 Jun 2021 04:02:15 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4FA29C061574; Wed, 23 Jun 2021 00:59:52 -0700 (PDT) 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.