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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 C3379C2D0BE for ; Thu, 5 Dec 2019 00:49:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8293D2077B for ; Thu, 5 Dec 2019 00:49:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="QBN+uUc9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8293D2077B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 358BB6B0D72; Wed, 4 Dec 2019 19:49:59 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 308116B0D73; Wed, 4 Dec 2019 19:49:59 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 245196B0D74; Wed, 4 Dec 2019 19:49:59 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0077.hostedemail.com [216.40.44.77]) by kanga.kvack.org (Postfix) with ESMTP id 10C826B0D72 for ; Wed, 4 Dec 2019 19:49:59 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id C4E62181AEF21 for ; Thu, 5 Dec 2019 00:49:58 +0000 (UTC) X-FDA: 76229255676.30.line72_914cb8073f848 X-HE-Tag: line72_914cb8073f848 X-Filterd-Recvd-Size: 3374 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Thu, 5 Dec 2019 00:49:58 +0000 (UTC) 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 10BF1224F8; Thu, 5 Dec 2019 00:49:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575506997; bh=0hBUZixU4pxatw7Ynjyrf3X1/Gzwtw5FCw/rDluEgZQ=; h=Date:From:To:Subject:In-Reply-To:From; b=QBN+uUc97gbN4e7JKg24uT57y1sS8QfsNFFCwvjAnppLDCBWKqxsNZWjdDWAaFL99 73RhPAXS2vWAXgOyDVZN3AOBg6Tq/moWAfEghgVn+BeAggBXSis7j9LHSYMYopuQpd aI+qxFMJHyWyRKmZYq4mZlLbRmbgRlpKjHY6Btxk= Date: Wed, 04 Dec 2019 16:49:56 -0800 From: Andrew Morton To: airlied@redhat.com, akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, gerald.schaefer@de.ibm.com, jrdr.linux@gmail.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, peterz@infradead.org, rcampbell@nvidia.com, thellstrom@vmware.com, torvalds@linux-foundation.org, will@kernel.org, willy@infradead.org, yuzhao@google.com Subject: [patch 05/86] mm/memory.c: replace is_zero_pfn with is_huge_zero_pmd for thp Message-ID: <20191205004956.Nwog-8x94%akpm@linux-foundation.org> In-Reply-To: <20191204164858.fe4ed8886e34ad9f3b34ea00@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: Yu Zhao Subject: mm/memory.c: replace is_zero_pfn with is_huge_zero_pmd for thp For hugely mapped thp, we use is_huge_zero_pmd() to check if it's zero page or not. We do fill ptes with my_zero_pfn() when we split zero thp pmd, but this is not what we have in vm_normal_page_pmd() -- pmd_trans_huge_lock() makes sure of it. This is a trivial fix for /proc/pid/numa_maps, and AFAIK nobody complains about it. Gerald Schaefer asked: : Maybe the description could also mention the symptom of this bug? : I would assume that it affects anon/dirty accounting in gather_pte_stats(), : for huge mappings, if zero page mappings are not correctly recognized. I came across this while I was looking at the code, so I'm not aware of any symptom. Link: http://lkml.kernel.org/r/20191108192629.201556-1-yuzhao@google.com Signed-off-by: Yu Zhao Acked-by: Andrew Morton Cc: Matthew Wilcox Cc: Ralph Campbell Cc: Will Deacon Cc: Peter Zijlstra Cc: "Aneesh Kumar K . V" Cc: Dave Airlie Cc: Thomas Hellstrom Cc: Souptick Joarder Cc: Gerald Schaefer Signed-off-by: Andrew Morton --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memory.c~mm-replace-is_zero_pfn-with-is_huge_zero_pmd-for-thp +++ a/mm/memory.c @@ -672,7 +672,7 @@ struct page *vm_normal_page_pmd(struct v if (pmd_devmap(pmd)) return NULL; - if (is_zero_pfn(pfn)) + if (is_huge_zero_pmd(pmd)) return NULL; if (unlikely(pfn > highest_memmap_pfn)) return NULL; _