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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 97DA5C61DCD for ; Fri, 28 Aug 2026 08:11:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 88D7C6B0092; Fri, 28 Aug 2026 04:11:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 866166B0095; Fri, 28 Aug 2026 04:11:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 77AFB6B0096; Fri, 28 Aug 2026 04:11:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 4DFF36B0092 for ; Fri, 28 Aug 2026 04:11:49 -0400 (EDT) Received: from smtpin23.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id BAE57C028B for ; Fri, 28 Aug 2026 08:11:48 +0000 (UTC) X-FDA: 85149959496.23.989880C Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf31.hostedemail.com (Postfix) with ESMTP id DD7F220004 for ; Fri, 28 Aug 2026 08:11:46 +0000 (UTC) Authentication-Results: imf31.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b="uzaOz1/o"; spf=pass (imf31.hostedemail.com: domain of yeoreum.yun@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=yeoreum.yun@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1787904707; b=ECXQrmbgB01/WuwxWaAne4mijWEWvxtpOd5Ij39w8++kui7zu6GF8JL7xRRteWOxd23Zju dt4kHQdToLRfvUrH5CGeIhXdEAxcnGUP2/J2pCNQPd3ViR3dUgUhzB4s980AZq45wckPxD goM51tQA4xkLhkLFvXt9Xgo1SFDAUEo= ARC-Authentication-Results: i=1; imf31.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b="uzaOz1/o"; spf=pass (imf31.hostedemail.com: domain of yeoreum.yun@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=yeoreum.yun@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1787904707; 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=QBbpZ4oLp0PjN5m3rXnDLE27ICVXyB5bUMovxnmt0SM=; b=Te8GU1fMnlTka0F+Vj7my62lEFTpwQPsGXDI8Qgo3joo34BwyElfjEJ1FdILywK64sOOAa SQkHwRfHfmYdKJyaIZFL3BVALCJ5m36cw9DUW0218ZXPDRdnBRyXvksjamUKIVQxoYAmQH LWIxVEm/jQrTCkzoUCgP1GKE3bA5z1o= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2A3D31688; Fri, 28 Aug 2026 01:11:42 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 794223F85F; Fri, 28 Aug 2026 01:11:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1787904705; bh=0I8+Oez4/Fvep0PwEfY0VNcmLGz/KZXfSGanwudrUEc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=uzaOz1/oJlW6bR6EV5BEwzUO3ZWDtOkiX8kQqTvtQIU+8Gstt90P/EfK0V5xpWkNj 68OSVH/YFW5zcfNWR7SNP8y2tmqKwNcLcLslb9UHvON4/PDR4Qmh3g6BKvZDU9lIay TSFu6UJYE3d/Bf8dt+2bNttsDZ8Ly2mXLvKiGusM= From: Yeoreum Yun Date: Fri, 28 Aug 2026 09:11:33 +0100 Subject: [PATCH v3 1/2] kselftest: mm: prevent random failure of huge page split for khugepaged MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260828-fix_split-v3-1-374022586a4b@arm.com> References: <20260828-fix_split-v3-0-374022586a4b@arm.com> In-Reply-To: <20260828-fix_split-v3-0-374022586a4b@arm.com> To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Kevin Brodsky Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Yeoreum Yun X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2554; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=0I8+Oez4/Fvep0PwEfY0VNcmLGz/KZXfSGanwudrUEc=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqkUK7V9mWLeZ9zL0R9lDWbj29vfP3HZbcACkU8 XLC7wYRzBeJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCapFCuwAKCRBt1cPRWsUx MzDVDACIL2ZyqeIY0AqiOfUb3ahEZz0Rfrp9OTdH2HaozEJu//mWMJfgISeHLcX1mIMhRKl1CGl YN1+8V4wMX3xvPj1HCQPgBmLNlyLnNm5+I8ELib45qcNWBhqxgzDiK9McBcHwkmhFZ6j+PqMvUY 60h8P9i7i5Am6skrXngCeQN5hpLtBGyJwRoVy3RJ5eloa8epQpkhri6oqRNaPzXgWhzkTrrswHp PhBjE83yLQQXvHWXx78YOkBQAHHRNdp/PdQ7NPdX3e1kb5QlDWKXlB78I8pokt5viPN6R/iurR6 U70GwNWPOz0yo0l+6xjpVCw5pS/xE6tsD2usTl3/WOPbdJssbinGjAT6AHq1Nv/dscvq+SHTJre CzFNwIc8ToSlZ1p8+lU3fOjsBUz2xRNKM4S2yIkLtNHJGhW7fYEMgnu9cPzX2u8IxR9kCVa9Xjb eHgKorOz6kpR+tC+1PpeU8FdefGOWSzKZlIyJMTw5FgBrZUKP8r4bqrvxl+KZ6GUtucnc= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DD7F220004 X-Stat-Signature: pmbyg3fdadg8ng9gsskobnm8f45zrgg4 X-Rspam-User: X-HE-Tag: 1787904706-491023 X-HE-Meta: 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 oQ4tRZX7 Thyt3/bnDx1xLEKRvyOUkX65E8pOVYyog2MhKprdT+sn07CQKoI3UngABTDy0vEwEc84sq7GmYrGp+TtS9/ygd6Qe7SsTTwIjafNe4IonjiJ4QeUe0UV6RevdteT/HcRvDXz1fuaBQIchyEfSnsLy4Jtcj/3s6+mXRiitPqPZ+doZPo9Yhv3eexGWsQ8ryUG+n23HA9HBbvq9dExdGb/8pY//CdHU6ljP/xyup3ij5eeOSSBnviHnYpTzT6tO4T2gRlzXE+6Ys62Rszvsq1WiLgf0Lg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: There're some random failure for split_huge_page_test when khugepaged collapses pages into pmd again which had split by the test. Prevent the khugepaged's collapses for split page by setting the mapped pmd-huge-page with MADV_NOHUGEPAGE before split. Reported-by: Kevin Brodsky Reviewed-by: Zi Yan Signed-off-by: Yeoreum Yun --- tools/testing/selftests/mm/split_huge_page_test.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c index 86a603692826..c718269a291f 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -180,6 +180,10 @@ static void verify_rss_anon_split_huge_page_all_zeroes(char *one_page, int nr_hp if (!rss_anon_before) ksft_exit_fail_msg("No RssAnon is allocated before split\n"); + /* Prevent khugepaged from collapsing the pages. */ + if (madvise(one_page, len, MADV_NOHUGEPAGE)) + ksft_print_msg("madvise(MADV_NOHUGEPAGE) failed\n"); + /* split all THPs */ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page, (uint64_t)one_page + len, 0); @@ -227,6 +231,10 @@ static void split_pmd_thp_to_order(int order) if (!check_huge_anon(one_page, 4 * pmd_pagesize, 4, pmd_pagesize)) ksft_exit_fail_msg("No THP is allocated\n"); + /* Prevent khugepaged from collapsing the pages. */ + if (madvise(one_page, len, MADV_NOHUGEPAGE)) + ksft_print_msg("madvise(MADV_NOHUGEPAGE) failed\n"); + /* split all THPs */ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page, (uint64_t)one_page + len, order); @@ -313,6 +321,10 @@ static void split_pte_mapped_thp(void) goto out; } + /* Prevent khugepaged from collapsing the pages. */ + if (madvise(thp_area, thp_area_size, MADV_NOHUGEPAGE)) + ksft_print_msg("madvise(MADV_NOHUGEPAGE) failed\n"); + /* Split all THPs through the remapped pages. */ write_debugfs(PID_FMT, getpid(), (uint64_t)page_area, (uint64_t)page_area + page_area_size, 0); @@ -542,6 +554,9 @@ static int create_pagecache_thp_and_fd(const char *testfile, size_t fd_size, ksft_test_result_skip("Pagecache folio split skipped\n"); return -2; } + /* Prevent khugepaged from collapsing the pages. */ + if (madvise(*addr, fd_size, MADV_NOHUGEPAGE)) + ksft_print_msg("madvise(MADV_NOHUGEPAGE) failed\n"); return 0; err_out_close: close(*fd); -- 2.43.0