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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32954C6FA8F for ; Thu, 24 Aug 2023 22:00:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243765AbjHXWA0 (ORCPT ); Thu, 24 Aug 2023 18:00:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243842AbjHXWAX (ORCPT ); Thu, 24 Aug 2023 18:00:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 801451BE9; Thu, 24 Aug 2023 15:00:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1BAE564AFF; Thu, 24 Aug 2023 22:00:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E83DC433C8; Thu, 24 Aug 2023 22:00:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1692914418; bh=ugfur8Szhw0qJJkTr4m18B2hI2Y31rP7OCZUC8QMIQg=; h=Date:To:From:Subject:From; b=rmKMHfAzBLNxdhymrtrFmO9YD5cLRInaZba3iTNRlGs2jYiJYT3CuwEtBdUgrsw4w DGwa8a4qYqQXyWShpRQQ/UkiwzPztYK64WtnLVGxrNY0uVSIMmLMyZLhQKuVfNWNpd jW45f3Dw/W2i6ZxCg3nf6eCWh929ubccWe3v4u/Y= Date: Thu, 24 Aug 2023 15:00:17 -0700 To: mm-commits@vger.kernel.org, yuzhao@google.com, willy@infradead.org, wangkefeng.wang@huawei.com, vishal.moola@gmail.com, stable@vger.kernel.org, shy828301@gmail.com, ryan.roberts@arm.com, minchan@kernel.org, david@redhat.com, fengwei.yin@intel.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] madvise-madvise_free_pte_range-dont-use-mapcount-against-large-folio-for-sharing-check.patch removed from -mm tree Message-Id: <20230824220018.6E83DC433C8@smtp.kernel.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The quilt patch titled Subject: madvise:madvise_free_pte_range(): don't use mapcount() against large folio for sharing check has been removed from the -mm tree. Its filename was madvise-madvise_free_pte_range-dont-use-mapcount-against-large-folio-for-sharing-check.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Yin Fengwei Subject: madvise:madvise_free_pte_range(): don't use mapcount() against large folio for sharing check Date: Tue, 8 Aug 2023 10:09:17 +0800 Commit 98b211d6415f ("madvise: convert madvise_free_pte_range() to use a folio") replaced the page_mapcount() with folio_mapcount() to check whether the folio is shared by other mapping. It's not correct for large folios. folio_mapcount() returns the total mapcount of large folio which is not suitable to detect whether the folio is shared. Use folio_estimated_sharers() which returns a estimated number of shares. That means it's not 100% correct. It should be OK for madvise case here. User-visible effects is that the THP is skipped when user call madvise. But the correct behavior is THP should be split and processed then. NOTE: this change is a temporary fix to reduce the user-visible effects before the long term fix from David is ready. Link: https://lkml.kernel.org/r/20230808020917.2230692-4-fengwei.yin@intel.com Fixes: 98b211d6415f ("madvise: convert madvise_free_pte_range() to use a folio") Signed-off-by: Yin Fengwei Reviewed-by: Yu Zhao Reviewed-by: Ryan Roberts Cc: David Hildenbrand Cc: Kefeng Wang Cc: Matthew Wilcox Cc: Minchan Kim Cc: Vishal Moola (Oracle) Cc: Yang Shi Cc: Signed-off-by: Andrew Morton --- mm/madvise.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/madvise.c~madvise-madvise_free_pte_range-dont-use-mapcount-against-large-folio-for-sharing-check +++ a/mm/madvise.c @@ -680,7 +680,7 @@ static int madvise_free_pte_range(pmd_t if (folio_test_large(folio)) { int err; - if (folio_mapcount(folio) != 1) + if (folio_estimated_sharers(folio) != 1) break; if (!folio_trylock(folio)) break; _ Patches currently in -mm which might be from fengwei.yin@intel.com are filemap-add-filemap_map_folio_range.patch rmap-add-folio_add_file_rmap_range.patch mm-convert-do_set_pte-to-set_pte_range.patch filemap-batch-pte-mappings.patch