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 310B6ECAAD3 for ; Wed, 14 Sep 2022 20:49:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 21CAA6B0072; Wed, 14 Sep 2022 16:49:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C9D36B0073; Wed, 14 Sep 2022 16:49:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 092DA8D0001; Wed, 14 Sep 2022 16:49:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id EDFAD6B0072 for ; Wed, 14 Sep 2022 16:49:30 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id C17F7801B2 for ; Wed, 14 Sep 2022 20:49:30 +0000 (UTC) X-FDA: 79911881700.11.C805A46 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf21.hostedemail.com (Postfix) with ESMTP id 2F1A71C00B7 for ; Wed, 14 Sep 2022 20:49:30 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 66D9661EF8; Wed, 14 Sep 2022 20:49:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FAFDC433C1; Wed, 14 Sep 2022 20:49:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1663188568; bh=gxi18X7LFH/rzmBn2mQG5Ml5iaadp1E8KUQNbCcmOCg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ak7zE0y0MZXOAPXK0wge44cCiiKzYa9if0LFLhCCq6RsPV5o9oSYnDid2X6mxW2zm veNajCDmhp+Y/EBBadU7Y8Ld5EAAMcwA/tf6CwqajNJKOpFh1yPePlgejHkA9j7ntQ Z/8Da/hLyefCb18wxNWThBSYjkYkpNT5wp7nQ3r8= Date: Wed, 14 Sep 2022 13:49:27 -0700 From: Andrew Morton To: Doug Berger Cc: Mike Kravetz , Muchun Song , Oscar Salvador , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] mm/hugetlb: correct demote page offset logic Message-Id: <20220914134927.16c229ccdc1a6b9da5d698c3@linux-foundation.org> In-Reply-To: <20220914190917.3517663-1-opendmb@gmail.com> References: <20220914190917.3517663-1-opendmb@gmail.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=ak7zE0y0; dmarc=none; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663188570; a=rsa-sha256; cv=none; b=Kb/lPpR1ZzbqEg8LX0ZTLcSat85WlzNPi5Q+exEaf1sJj3INIt3rzHh64NP94XstODc2fJ I/vvdFfb9eSRi0OjZaCPpHTpby7XIBmOv5J+Tb4JZ1e3eInKOf2z15itZg8UOUuyLCdrfS tStCE+Z/EkRzURzD0XjmeUaMwedWL1Y= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663188570; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=gxi18X7LFH/rzmBn2mQG5Ml5iaadp1E8KUQNbCcmOCg=; b=ZOGzYFEw32tOrxHrkRyplMWz7qxNsi0Dw8IC62J9L3+2puA/g2iYoJOIsxb2Du68mEmrM9 mZD6giomU/gKyNu606lu4oKKeTYZ+wgH2GZYCtwC0UfobRb6fQx/lrxWakXuE88jOoP8X1 fWi/Ky93JH2p+KaW9Vpfc305Gx0TMTk= X-Rspam-User: Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=ak7zE0y0; dmarc=none; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 2F1A71C00B7 X-Stat-Signature: k6ahbfsk1y6oyxe8pn987p3yc4t7uoj8 X-HE-Tag: 1663188570-751123 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 Wed, 14 Sep 2022 12:09:17 -0700 Doug Berger wrote: > With gigantic pages it may not be true that struct page structures > are contiguous across the entire gigantic page. The nth_page macro > is used here in place of direct pointer arithmetic to correct for > this. What were the user-visible runtime effects of this bug?