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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BD09EE7FE3 for ; Fri, 8 Sep 2023 13:10:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243410AbjIHNKE (ORCPT ); Fri, 8 Sep 2023 09:10:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229699AbjIHNKD (ORCPT ); Fri, 8 Sep 2023 09:10:03 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D51C19B5 for ; Fri, 8 Sep 2023 06:09:59 -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=QRChBe5PZMuw+zPsASEy2dEzmm9n/h3rkYmxC0tWOYs=; b=Hdnr4ID2aydT9hhHxq/HiSr6nU bDqb2vDxhqGdqAR+KQMM0w/2ASZoQnHLYp2wKk9Dr1eiiE0xldEpXPAnEVkJ2ld1eLFt7Ey+6pkAO UJ4qRm4wQJRhY3UHRXUuhPjgECoUVqXfa+pR2YiVMylpHa3kpyAvSQK2m+vUy3Q69Kgu4UB/B0fxB eM3F+a2vlX7pWcgVnFeIn4hLq1UJXLG78tQMD8A44lwv4PHOfbGqPewjG1feq9GN4bIW+gT866lNV giXQUgFsNPX6DC44yKe9AFFzttXmqVPT/5aP83Q08/XIo4g/0kn/NqqaURNgRB+BY3YpfLeAKoUOe kEG3cBdA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qebFB-000HDw-0T; Fri, 08 Sep 2023 13:09:53 +0000 Date: Fri, 8 Sep 2023 14:09:52 +0100 From: Matthew Wilcox To: Ankur Arora Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, mgorman@suse.de, peterz@infradead.org, rostedt@goodmis.org, tglx@linutronix.de, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com Subject: Re: [PATCH v2 3/9] mm/huge_page: cleanup clear_/copy_subpage() Message-ID: References: <20230830184958.2333078-1-ankur.a.arora@oracle.com> <20230830184958.2333078-4-ankur.a.arora@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230830184958.2333078-4-ankur.a.arora@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 30, 2023 at 11:49:52AM -0700, Ankur Arora wrote: > @@ -5945,9 +5935,7 @@ static int __clear_huge_page( > /* Process subpages at the end of huge page */ > for (i = pages_per_huge_page - 1; i >= 2 * n; i--) { > cond_resched(); > - ret = process_subpage(addr + i * PAGE_SIZE, i, arg); > - if (ret) > - return ret; > + clear_user_highpage(page + i, addr + i * PAGE_SIZE); It's possible for a 1GB page to cross a memmap discontiguity. This needs to be: clear_user_highpage(nth_page(page, i), addr + i * PAGE_SIZE); (similarly in other places)