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 7C68EC9830E for ; Thu, 24 Sep 2026 19:11:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 971A76B0092; Thu, 24 Sep 2026 15:11:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9495A6B0093; Thu, 24 Sep 2026 15:11:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 885CE6B0095; Thu, 24 Sep 2026 15:11:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 652226B0092 for ; Thu, 24 Sep 2026 15:11:39 -0400 (EDT) Received: from smtpin08.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 75C1A1C2D6E for ; Thu, 24 Sep 2026 19:11:37 +0000 (UTC) X-FDA: 85249599834.08.18B6FA9 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf28.hostedemail.com (Postfix) with ESMTP id 651A2C0010 for ; Thu, 24 Sep 2026 19:11:35 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=LBHSCsIo; spf=pass (imf28.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=1790277095; 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=13hOtGo7xgx1AZMH7zv3V36SDiF8l0tOoXqJVV/03R4=; b=bRXSa54LJV41bAOOgapZa6ZFxSBTvMK+AZNnRmNflIadiMZZhMq/XZ+hwOXBW1tl4dwH2T IXyMusq828GsTXo7vi2qZY5bER9WL0prvr6sgfDiPm8lR9zt30XCkK9GSe7WQOcWS0U64X R2uEROlmRTEP9uyFCbpsC9zqYx6Yvck= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=arm.com header.s=foss header.b=LBHSCsIo; spf=pass (imf28.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=1790277095; b=WjonOUuZXTKEsh6BRtAsCSweC8U7mpTehhN7cuxTArT0h0PZr0qa/L8fJf8eA0UPau52PX 6P2rYMf36kTvilf8qteit5ZXijxHyni5QIAMVNgHDBo+tEThuMNSFSFRGAX3Gekhx/Xv5q xuoRGkKi97Ha9FJzJP/BN1OVrQLPUR4= 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 B4DCB1E8D; Thu, 24 Sep 2026 12:11:29 -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 DE7FC3F86F; Thu, 24 Sep 2026 12:11:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790277093; bh=Cp04Flq0uAtUr4B5wboFRQwEJBDejnd6LVB0IHI+q3A=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=LBHSCsIovix4NKw2QVz9ASL0qMoTQSCzI/HtXhZN1rnUVLy/HckTBXKlMu7oSmxhv LBhZh+4Cp2BaUS1ZvfBbrQFQ+K+r+00tZJRMnxLWbrqj+kEVcKay3Ah1vmsSGJMGN4 HDWR0b2QRs4sTRc5zU+jVPOFwW/b0XYggwieCYkc= From: Yeoreum Yun Date: Thu, 24 Sep 2026 20:11:16 +0100 Subject: [PATCH v8 1/4] 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: <20260924-fix_split-v8-1-cba7359d882a@arm.com> References: <20260924-fix_split-v8-0-cba7359d882a@arm.com> In-Reply-To: <20260924-fix_split-v8-0-cba7359d882a@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=2770; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=Cp04Flq0uAtUr4B5wboFRQwEJBDejnd6LVB0IHI+q3A=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqtXXcbujZXi+XpYIK57ZqF2h1gdqKzbbdnd1tc /WPH1DdxI+JAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCarV13AAKCRBt1cPRWsUx M8E5DAC0eBy5F+3A6LbX3CvhUrMPz514WgNRmJz6yMM1DmIcrO7HnAvnTU5LrUm1sFNxjaOxsHF Ocg7mTwtnP6axffBSXJbyo8NmCs8YY1iDpbLSeigMOg2Jw3IHcr6XYELBb0N8cGuiW4HlbAuXc1 lkNvBqOeNgKaomCSOv7Rgo+iPVkPM/z+DVpeeEh8a3j8AOuShl2vPcmlyaQRdkhNvtJNee68WcG KwudWeAIVwT1JdokYRp4/m+bMBL4O4z8laxQoacJkAfkC1vsUYdrXhPm8b+p8JEMXOBlAupxPyC bFpUiNleofMa99dxQQHXo6El1xYgUDVLHS45V05E+eoaXPlfGI8BgHJa1odRzv9J/EjiwDgv1Ft 2zUmDRpY1iHc3y9hDmCdb3H3JmH81dNXppXP82mz2a6/vYixcVbxzZUqNPj8Aey9FMiLmTfkPnD SBHwFTvyyInl2c4MuI+7rIsXwBLuZmROBR6DieFJGbn755fOeWCcjuoSImQlauiE599BQ= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 651A2C0010 X-Stat-Signature: 1ifhsssjbzewm6e6ggo53hx7pygfsmof X-HE-Tag: 1790277095-880362 X-HE-Meta: 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 waD+f8Y/ Wf0fLInXYp92wKgWX43q02BUz22FYE0B+2p5OftLolBJAj0C6TZWeimOpdXJf+i6P77HVOw/qvsDfDMdCxQ1hnPMuTxpfQIdTj6dDnZAZ6bIqh5+MmMMC/i1GCRPVxSnLXl5l9IBZ8cDhzI+pghKKsihbHhewe6QVELsrIODg1qfhcHcAhTz3Xn1O9V8KHg5/a9htPuHcEHFEX9u9wXuRv55kd50j/MIDebY+wo0e73x5PHXzj45pxyeSe1comH13DW0llQ52lNO4EDWqL7EBRRxAwMQSH8ZXdR9cWlXUrGX8wY4ZWoZlis7n1A== 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. Suggested-by: Kevin Brodsky Suggested-by: Lorenzo Stoakes (ARM) Reviewed-by: Lorenzo Stoakes (ARM) Reviewed-by: Zi Yan Acked-by: David Hildenbrand (Arm) Signed-off-by: Yeoreum Yun --- tools/testing/selftests/mm/split_huge_page_test.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c index c5d96a4b1db3..ef4058662b91 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -108,6 +108,18 @@ static char *allocate_zero_filled_hugepage(size_t len) return result; } +static void disable_khugepaged(void *addr, size_t len) +{ + /* + * Disables khugepaged from collapsing THPs in range, existing THP + * pages remain. + */ + if (!madvise(addr, len, MADV_NOHUGEPAGE)) + return; + + ksft_exit_fail_msg("MADV_NOHUGEPAGE failed, err=%d\n", errno); +} + static void verify_rss_anon_split_huge_page_all_zeroes(char *one_page, int nr_hpages, size_t len) { unsigned long rss_anon_before, rss_anon_after; @@ -120,6 +132,8 @@ 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"); + disable_khugepaged(one_page, len); + /* split all THPs */ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page, (uint64_t)one_page + len, 0); @@ -167,6 +181,8 @@ 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"); + disable_khugepaged(one_page, len); + /* split all THPs */ write_debugfs(PID_FMT, getpid(), (uint64_t)one_page, (uint64_t)one_page + len, order); @@ -215,6 +231,8 @@ static void split_pte_mapped_thp(void) goto out; } + disable_khugepaged(thp_area, thp_area_size); + /* * To challenge spitting code, we will mremap a single page of each * THP (page[i] of thp[i]) in the thp_area into page_area. This will @@ -482,6 +500,7 @@ 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; } + disable_khugepaged(*addr, fd_size); return 0; err_out_close: close(*fd); -- 2.43.0