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[2620:137:e000::1:20]) by mx.google.com with ESMTP id u137-20020a63798f000000b00438894246e8si16989476pgc.169.2022.09.14.13.53.33; Wed, 14 Sep 2022 13:54:09 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linux-foundation.org header.s=korg header.b=ak7zE0y0; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229812AbiINUtz (ORCPT + 99 others); Wed, 14 Sep 2022 16:49:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229820AbiINUtc (ORCPT ); Wed, 14 Sep 2022 16:49:32 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F4011B3C; Wed, 14 Sep 2022 13:49:29 -0700 (PDT) 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 EE60E61D3A; Wed, 14 Sep 2022 20:49:28 +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 X-Spam-Status: No, score=-8.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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?