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=DKIM_INVALID,DKIM_SIGNED, 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 0C717C433EA for ; Mon, 29 Jun 2020 18:54:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C81E720656 for ; Mon, 29 Jun 2020 18:54:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="FcgBnyLz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C81E720656 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 640118D000C; Mon, 29 Jun 2020 14:54:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5F0138D0005; Mon, 29 Jun 2020 14:54:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5057A8D000C; Mon, 29 Jun 2020 14:54:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0063.hostedemail.com [216.40.44.63]) by kanga.kvack.org (Postfix) with ESMTP id 4071C8D0005 for ; Mon, 29 Jun 2020 14:54:41 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 04D5B181AC9C6 for ; Mon, 29 Jun 2020 18:54:41 +0000 (UTC) X-FDA: 76983150762.24.beast45_4e1709626e71 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin24.hostedemail.com (Postfix) with ESMTP id C71731A4A0 for ; Mon, 29 Jun 2020 18:54:40 +0000 (UTC) X-HE-Tag: beast45_4e1709626e71 X-Filterd-Recvd-Size: 2730 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf24.hostedemail.com (Postfix) with ESMTP for ; Mon, 29 Jun 2020 18:54:40 +0000 (UTC) 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=rHCxMAr5/QRYYlY+wj4xHleNaD2XeEWYXXCLc6cZruE=; b=FcgBnyLz9Fx+QZO0k3eTm2zZzp 8EVRqSvt68Krztk0t+uF3tZ21nrcR1yz6hb0G88EzU0qqx9cCe9VWnNBQuZ9EsQON5xIA5iUPrlrI UgQ2Q9LXVVjtgKQaAm56BbNT9kDyk0OL6M5HuFqTqSi84OWOamE+BGgDJRAMU5uxhaaR5WZigdX5S l3NjtpOxj3DDE8aCdHpgY3vrdxRtd+qyX0keOdatEC/OrFDi/KyyOCSr+haxFZA8JYKTgqSxUVuNX mIKdaHVxqriwZ2wsLyjmf2ZqRXLSpA139CGNu1kmPexQ2Lh9oLG761UH4YTiXpRZpYW0rmrrUKIi2 +N9eW0Ow==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jpyvK-00006r-AV; Mon, 29 Jun 2020 18:54:35 +0000 Date: Mon, 29 Jun 2020 19:54:34 +0100 From: Matthew Wilcox To: Mike Kravetz Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , "Kirill A . Shutemov" , Andrew Morton , stable@kernel.org Subject: Re: [PATCH] hugetlb: fix pages per hugetlb calculation Message-ID: <20200629185434.GI25523@casper.infradead.org> References: <20200629185003.97202-1-mike.kravetz@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200629185003.97202-1-mike.kravetz@oracle.com> X-Rspamd-Queue-Id: C71731A4A0 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 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, Jun 29, 2020 at 11:50:03AM -0700, Mike Kravetz wrote: > The routine hpage_nr_pages() was incorrectly used to calculate the > number of base pages in a hugetlb page. hpage_nr_pages is designed > to be called for THP pages and will return HPAGE_PMD_NR for hugetlb > pages of any size. > > Due to the context in which hpage_nr_pages was called, it is unlikely > to produce a user visible error. The routine with the incorrect call > is only exercised in the case of hugetlb memory error or migration. > In addition, this would need to be on an architecture which supports > huge page sizes less than PMD_SIZE. And, the vma containing the huge > page would also need to smaller than PMD_SIZE. > > Fixes: c0d0381ade79 ("hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization") > Cc: stable@kernel.org > Signed-off-by: Mike Kravetz Reviewed-by: Matthew Wilcox (Oracle) Inadvertently-Reported-by: Matthew Wilcox (Oracle)