From patchwork Thu Apr 28 15:42:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 567479 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 AA2C6C433F5 for ; Thu, 28 Apr 2022 15:42:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349403AbiD1Ppt (ORCPT ); Thu, 28 Apr 2022 11:45:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33252 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344055AbiD1Ppo (ORCPT ); Thu, 28 Apr 2022 11:45:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06EFAAC04B; Thu, 28 Apr 2022 08:42:29 -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 96F8A61F95; Thu, 28 Apr 2022 15:42:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E38AC385A0; Thu, 28 Apr 2022 15:42:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651160548; bh=W6JZHURiD6S8sCBWTVgKCEUD2N8YrqtIi8H2lqDIUIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2FTCNuEMytEk2OLSJR+am6TFPzLZzc9hAU1K91ZblJPHOU3wXQN8kU6njVxB8Py/l M36IPZ6KvEBBoep7xbkFbx5r+H3i9WqDDOrSesrxA394/eBd4mGWEqQoOCqjrRfn/Q QskWcYrWsaZI4jQM1mJ2aVtC2QaJznoMfzJqN8Qc= From: Greg Kroah-Hartman To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Muchun Song , Zi Yan , Axel Rasmussen , David Rientjes , Fam Zheng , "Kirill A . Shutemov" , Lars Persson , Mike Kravetz , Peter Xu , Xiongchun Duan , Andrew Morton , Linus Torvalds , Greg Kroah-Hartman Subject: [PATCH AUTOSEL 02/14] mm: fix missing cache flush for all tail pages of compound page Date: Thu, 28 Apr 2022 17:42:10 +0200 Message-Id: <20220428154222.1230793-2-gregkh@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220428154222.1230793-1-gregkh@linuxfoundation.org> References: <20220428154222.1230793-1-gregkh@linuxfoundation.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2363; i=gregkh@linuxfoundation.org; h=from:subject; bh=tzQoyaSqlxtKRFY8pVM4ItgoSNdr8h3zMFKbCiWeB+o=; b=owGbwMvMwCRo6H6F97bub03G02pJDElZW++4TAoPCs68vr7igM3rJk+lvg4Rixv6869mVp2wv2Cx +2N3RywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEzk/FeGBWdvSqqovPy9V3b1Oqf2r0 sqt79pk2SYHyd3/rzal4VSM3hYg4XL8hQ/L9jwCAA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Muchun Song commit 2771739a7162782c0aa6424b2e3dd874e884a15d upstream. The D-cache maintenance inside move_to_new_page() only consider one page, there is still D-cache maintenance issue for tail pages of compound page (e.g. THP or HugeTLB). THP migration is only enabled on x86_64, ARM64 and powerpc, while powerpc and arm64 need to maintain the consistency between I-Cache and D-Cache, which depends on flush_dcache_page() to maintain the consistency between I-Cache and D-Cache. But there is no issues on arm64 and powerpc since they already considers the compound page cache flushing in their icache flush function. HugeTLB migration is enabled on arm, arm64, mips, parisc, powerpc, riscv, s390 and sh, while arm has handled the compound page cache flush in flush_dcache_page(), but most others do not. In theory, the issue exists on many architectures. Fix this by not using flush_dcache_folio() since it is not backportable. Link: https://lkml.kernel.org/r/20220210123058.79206-3-songmuchun@bytedance.com Fixes: 290408d4a250 ("hugetlb: hugepage migration core") Signed-off-by: Muchun Song Reviewed-by: Zi Yan Cc: Axel Rasmussen Cc: David Rientjes Cc: Fam Zheng Cc: Kirill A. Shutemov Cc: Lars Persson Cc: Mike Kravetz Cc: Peter Xu Cc: Xiongchun Duan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/migrate.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 086a36637467..fc0e14ecd42a 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -916,9 +916,12 @@ static int move_to_new_page(struct page *newpage, struct page *page, if (!PageMappingFlags(page)) page->mapping = NULL; - if (likely(!is_zone_device_page(newpage))) - flush_dcache_page(newpage); + if (likely(!is_zone_device_page(newpage))) { + int i, nr = compound_nr(newpage); + for (i = 0; i < nr; i++) + flush_dcache_page(newpage + i); + } } out: return rc;