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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 DD087C433DF for ; Fri, 16 Oct 2020 02:42:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97A5E2087D for ; Fri, 16 Oct 2020 02:42:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602816136; bh=zHASiUDz758IL+Etgbjq3oRtoew3nAEe4RdntxV5XTM=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=HMOgX28Xe5E/+zO16maPRktD3ScdLhJY05HPZHap/0rtaYTsKAEWeWGDju2xUwzRz 1ywDWyHx4nsXxGnFwDCN7whu+ODGqwHnja3voM6pioisPwB7xr4nXQqmVJD4ivREpv 4rBZHOJ7JppgE8zZGH/8tzTKFMpqzUSffaV8oPp8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404298AbgJPCmQ (ORCPT ); Thu, 15 Oct 2020 22:42:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:57714 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728688AbgJPCmQ (ORCPT ); Thu, 15 Oct 2020 22:42:16 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E09312087D; Fri, 16 Oct 2020 02:42:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602816134; bh=zHASiUDz758IL+Etgbjq3oRtoew3nAEe4RdntxV5XTM=; h=Date:From:To:Subject:In-Reply-To:From; b=m/roYdpTtJszbqwKr8/8JWGW9j6tCwY9zNfLrJuRFf4Sso920sWI7TZfv9oN+ErH5 Syjihra/fP+0z5+zjYPF4tu0B/e1+EB7vUdZPqSUJ96i8xSz8Uru8JElMEooTCh0g/ RDlSTvImfcwYXZhFl+5J3k5c6FqzqzcPA58mvSXE= Date: Thu, 15 Oct 2020 19:42:13 -0700 From: Andrew Morton To: akpm@linux-foundation.org, kirill@shutemov.name, linux-mm@kvack.org, mm-commits@vger.kernel.org, sjpark@amazon.de, torvalds@linux-foundation.org, willy@infradead.org, ying.huang@intel.com Subject: [patch 022/156] mm/huge_memory: fix total_mapcount assumption of page size Message-ID: <20201016024213.uqBvLymdF%akpm@linux-foundation.org> In-Reply-To: <20201015192732.f448da14e9854c7cb7299956@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: "Kirill A. Shutemov" Subject: mm/huge_memory: fix total_mapcount assumption of page size File THPs may now be of arbitrary order. Link: https://lkml.kernel.org/r/20200908195539.25896-5-willy@infradead.org Signed-off-by: Kirill A. Shutemov Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: SeongJae Park Cc: Huang Ying Signed-off-by: Andrew Morton --- mm/huge_memory.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/mm/huge_memory.c~mm-huge_memory-fix-total_mapcount-assumption-of-page-size +++ a/mm/huge_memory.c @@ -2494,7 +2494,7 @@ static void __split_huge_page(struct pag int total_mapcount(struct page *page) { - int i, compound, ret; + int i, compound, nr, ret; VM_BUG_ON_PAGE(PageTail(page), page); @@ -2502,16 +2502,17 @@ int total_mapcount(struct page *page) return atomic_read(&page->_mapcount) + 1; compound = compound_mapcount(page); + nr = compound_nr(page); if (PageHuge(page)) return compound; ret = compound; - for (i = 0; i < HPAGE_PMD_NR; i++) + for (i = 0; i < nr; i++) ret += atomic_read(&page[i]._mapcount) + 1; /* File pages has compound_mapcount included in _mapcount */ if (!PageAnon(page)) - return ret - compound * HPAGE_PMD_NR; + return ret - compound * nr; if (PageDoubleMap(page)) - ret -= HPAGE_PMD_NR; + ret -= nr; return ret; } _