From nobody Fri Apr 3 08:17:22 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2BD8C6FA82 for ; Wed, 14 Sep 2022 19:10:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229635AbiINTKH (ORCPT ); Wed, 14 Sep 2022 15:10:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229550AbiINTKE (ORCPT ); Wed, 14 Sep 2022 15:10:04 -0400 Received: from mail-qk1-x72e.google.com (mail-qk1-x72e.google.com [IPv6:2607:f8b0:4864:20::72e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A0DC2ED60; Wed, 14 Sep 2022 12:10:03 -0700 (PDT) Received: by mail-qk1-x72e.google.com with SMTP id c19so9734995qkm.7; Wed, 14 Sep 2022 12:10:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date; bh=6mBQHGkTCxpZ0kR+Uol1DB+Rk5F3r94azBv7C4epuC0=; b=Dw+JcD8DgkClgEkMagfiLANjV0/pvsu8mhEfMYKS7oDGdcZfuKNeFhI/Aoq7gPfQLV e8Kwx4FZhkAXPB+vBkt9h4Jdvp+0RBQ4LU+E4Xgr9bdlw1/FqhFU29nRGFQ9zTfZw38Z p7Je6UJUAwa54gPy3e+9UPpKoky64QyvHprd5ErvXlrdCDEcyXN6yTB9GhUbzi0AK5LE HOEpB2MnXRM+djEY0AvyrOxocKyT8YTNfyTMFmxLDwH+i94Zyu1JIR6aGOIpi60vgvOb WfgRj9PkKGvrrMSBQK7ouYKhoPR+A3L2SeloAaG4l7KYZViqKsgcPirutkSJJpSAvfCY U9sA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date; bh=6mBQHGkTCxpZ0kR+Uol1DB+Rk5F3r94azBv7C4epuC0=; b=EJ7MvtnmSGvBYcw+KukO66V4/Ny+fepM6cq+g10KHx6g8iFDoxP3ZLeF5RBeu7k0f/ lIYzLTfoWE4Jxyrui0HKG7JaT2Crx+sLLzMZgF1z26VR7fUCiFlVdPGZQs4TQunD1zRD TEsf+B8RQbM4uLCUp9S+QHKnlpI7bpSNcHQ/w0HoW/yi4gG0pvu5eEPzF1cnJM1OSfUL 8xNMsehjNVNkCbTS8JT/5YBMDDNAYTsvSa0mgJ6ptLS1HTVbvqt+TOlAONBctlfYsQ6D 28AEL7F5iO0MlVDLlT+2C+vn934INm0O3jufckVSIVYzRWt7AJnSjJdAkRKdGXidr3SN sfZQ== X-Gm-Message-State: ACgBeo32yXgEPcHJxECtcOQEWLk3kC0fh+l3JViXa05ZPPhXtSKl/Clw wfApYzsRk4dY5kTV2zpljapeODrRHYg= X-Google-Smtp-Source: AA6agR6/cTAVNB2gJ6Q5yLayiUSp9J8axMaA2UvkltnAQknb0qPfdRdMCbKdsCS63D4nEi+1IcaxrQ== X-Received: by 2002:a05:620a:4447:b0:6c6:c438:1ced with SMTP id w7-20020a05620a444700b006c6c4381cedmr28568302qkp.658.1663182602724; Wed, 14 Sep 2022 12:10:02 -0700 (PDT) Received: from stbirv-lnx-3.igp.broadcom.net ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id p8-20020a05622a00c800b0035bb8168daesm2300105qtw.57.2022.09.14.12.09.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Sep 2022 12:10:01 -0700 (PDT) From: Doug Berger To: Mike Kravetz , Muchun Song Cc: Andrew Morton , Oscar Salvador , linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Doug Berger Subject: [PATCH] mm/hugetlb: correct demote page offset logic Date: Wed, 14 Sep 2022 12:09:17 -0700 Message-Id: <20220914190917.3517663-1-opendmb@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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. Fixes: 8531fc6f52f5 ("hugetlb: add hugetlb demote page support") Signed-off-by: Doug Berger Cc: Reviewed-by: Anshuman Khandual Reviewed-by: Mike Kravetz Reviewed-by: Oscar Salvador --- mm/hugetlb.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index e070b8593b37..0bdfc7e1c933 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3420,6 +3420,7 @@ static int demote_free_huge_page(struct hstate *h, st= ruct page *page) { int i, nid =3D page_to_nid(page); struct hstate *target_hstate; + struct page *subpage; int rc =3D 0; =20 target_hstate =3D size_to_hstate(PAGE_SIZE << h->demote_order); @@ -3453,15 +3454,16 @@ static int demote_free_huge_page(struct hstate *h, = struct page *page) mutex_lock(&target_hstate->resize_lock); for (i =3D 0; i < pages_per_huge_page(h); i +=3D pages_per_huge_page(target_hstate)) { + subpage =3D nth_page(page, i); if (hstate_is_gigantic(target_hstate)) - prep_compound_gigantic_page_for_demote(page + i, + prep_compound_gigantic_page_for_demote(subpage, target_hstate->order); else - prep_compound_page(page + i, target_hstate->order); - set_page_private(page + i, 0); - set_page_refcounted(page + i); - prep_new_huge_page(target_hstate, page + i, nid); - put_page(page + i); + prep_compound_page(subpage, target_hstate->order); + set_page_private(subpage, 0); + set_page_refcounted(subpage); + prep_new_huge_page(target_hstate, subpage, nid); + put_page(subpage); } mutex_unlock(&target_hstate->resize_lock); =20 --=20 2.25.1