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 ADA28C433F5 for ; Mon, 10 Jan 2022 08:30:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 376D26B009F; Mon, 10 Jan 2022 03:30:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 324486B00A0; Mon, 10 Jan 2022 03:30:01 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 213CF6B00A1; Mon, 10 Jan 2022 03:30:01 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0198.hostedemail.com [216.40.44.198]) by kanga.kvack.org (Postfix) with ESMTP id 10B816B009F for ; Mon, 10 Jan 2022 03:30:01 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id A6D498D6F3 for ; Mon, 10 Jan 2022 08:30:00 +0000 (UTC) X-FDA: 79013704560.09.326485E Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf09.hostedemail.com (Postfix) with ESMTP id 56B1914000A for ; Mon, 10 Jan 2022 08:30:00 +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=NyEGaIYhwQZ0SG9l+yYLvyNiaRvR0QxLhqApt8jZaKE=; b=JrJKSdtRxHrQN7s9iBLyOoykSx JQgRIG1E8NRFWcqaELsPNkiTVCRX2/wUbBDRVPWvCEajPXq6zCjhHP5NGO99omk/Zv95pacaHGDOJ hhkZt6Sv+AigS/UZQCcsI6w7wrvNMFbvn9sI3ryC4vNkjic+3WZJc90x0wsLRN2my5OL8MqdCCeyV M7KEDcVjiG3xVwLM9Seo5FPxw10ojtFlyaonjrV++hKEIR54aOE/4IYI9ZgvjIwh6xPUIFk+517Lg DTZx0anNWCCJjpJfSwxCdEtvkGw/PXMa+DNijgapdP/kcaR5kppYrJ0NuhjMSyfROk28/nmvD7edy 7dMuLguw==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1n6q3y-009sLI-VK; Mon, 10 Jan 2022 08:29:58 +0000 Date: Mon, 10 Jan 2022 00:29:58 -0800 From: Christoph Hellwig To: "Matthew Wilcox (Oracle)" Cc: linux-mm@kvack.org, John Hubbard , Christoph Hellwig , William Kucharski , linux-kernel@vger.kernel.org, Jason Gunthorpe Subject: Re: [PATCH v2 06/28] gup: Fix some contiguous memmap assumptions Message-ID: References: <20220110042406.499429-1-willy@infradead.org> <20220110042406.499429-7-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220110042406.499429-7-willy@infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Rspamd-Queue-Id: 56B1914000A X-Stat-Signature: f6b9tkxcuwo3fknwcuxjqsausntnfeic Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=JrJKSdtR; dmarc=none; spf=none (imf09.hostedemail.com: domain of BATV+996bc53df2b455107366+6714+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+996bc53df2b455107366+6714+infradead.org+hch@bombadil.srs.infradead.org X-Rspamd-Server: rspam11 X-HE-Tag: 1641803400-414246 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 Mon, Jan 10, 2022 at 04:23:44AM +0000, Matthew Wilcox (Oracle) wrote: > Several functions in gup.c assume that a compound page has virtually > contiguous page structs. This isn't true for SPARSEMEM configs unless > SPARSEMEM_VMEMMAP is also set. Fix them by using nth_page() instead of > plain pointer arithmetic. So is this an actualy bug that need a Fixes tag, or do all architectures that support THP and sparsemem use SPARSEMEM_VMEMMAP? > + page = nth_page(head, (addr & (sz-1)) >> PAGE_SHIFT); Would be nice to fix the indeation for sz - 1 while you're at it. Otherwise looks good: Reviewed-by: Christoph Hellwig