From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B0FE33BD629; Thu, 20 Aug 2026 19:40:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787254840; cv=none; b=nnrE3p+fWrut/5xw+PgLXXwbB8VcWGfB7OZ/FN62xde9SLjwTcZtQKcTapf1BA2MQ6oElh7wylNSFtKITi8jrvMVJHQ9TBAiAwX44alD8rFufHSVP956Scbya2yCH5WYSrIhSLcxrmToYmJCCY5t8kFoax6t3FcD/TOBA9ACYi4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787254840; c=relaxed/simple; bh=7pjEAmcXmpKnIzyuI0Xt2csvEi1hxzh7Ykp3uUVDmPM=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=hAiTX8KXZWLzGBypX3P9BKeNTLLrqv5+h6+kLrXLs6wiGDH0uGw2NwkXquDzXDVzSePmRIvJdn9GGJ/usqjpotkjv+JekKGgRL6+ac69fe6JzOzTu00A+qi7bwDVTnF8Ks9gatXScKtv347Y7V/+W5Zo+65Nf0hiPKEk2suJ5iw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=OIs7PUjl; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="OIs7PUjl" 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 94FBC202C; Thu, 20 Aug 2026 12:40:32 -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 DFB3E3F763; Thu, 20 Aug 2026 12:40:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1787254836; bh=7pjEAmcXmpKnIzyuI0Xt2csvEi1hxzh7Ykp3uUVDmPM=; h=From:Subject:Date:To:Cc:From; b=OIs7PUjlgsvSxEm+4KOPIhXSUEtqz+Dveg3IA6WSTrV09DJzBRAmSh2p2jYzEhnwi ZHbtmhs10iUTaB4haVYZ/hbio7uyPa763254zj4Ui0JB3dxvFix8/Lmjh5Ue/O1sMo hpc/QnbTR2C0OWNI8H9BDVZZJi2DVUgYwEFooaH4= From: Yeoreum Yun Subject: [PATCH 0/2] kselftest: mm: fix some failure of split_huge_page_test Date: Thu, 20 Aug 2026 20:40:14 +0100 Message-Id: <20260820-fix_split-v1-0-ab430c58c7cf@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-B4-Tracking: v=1; b=H4sIAB5Yh2oC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDIzMDCyMD3bTMivjigpzMEt00ExNLY8vUZBOTJAsloPqColSgJNis6NjaWgB DAyKQWwAAAA== 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=1755; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=7pjEAmcXmpKnIzyuI0Xt2csvEi1hxzh7Ykp3uUVDmPM=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqh1gwm/jKRe0lLHpiBKW9B83UVm1ikv0xur6vY zN6/CFlkFqJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCaodYMAAKCRBt1cPRWsUx M27iC/44KXI87DFCucVPVj7t0kMHHMnV1u1Ador5n0t/pcbAdBlu4sxJ4lxoytEylySpm7nFeRr Fe/qAcPr18DBZt530yAXyQqO/iQ9mAs66y0zhYhY+GMPaa/qvKBVjbMfkUgONkn/dz2F5DXvoiq Jh1gQq0TcAJkeKZpGSheCauvaGJO0PAIv7Pdzr41qvyATk9zMWxb8ndjmfM3UKMOw3H2wdJChGq ktET/ddQXL36nihkEwmzwUHnyGGSv/j7jnSqeaIyG35YbCb4D1TlYZi4o8P28DW4nfPA/EYxlzw vJp4hdRGPzmpVYhlVE76m/AKKaj4PxexIDSGovO2SBfVa1rmFJLdCk7Ikcbm4mOaC+iIt+3xKhU 6L7nJWLeaev20itWCB0ZZK7/vWbGlxIYFgRxzp+0ijbooqaMTBQnHODW/T/0mNqryXXWOPfGf9f yG+bI94CnXx2g7jTJgrfXKcqcnOYyl8QKiNRWPwu8aevgxkTd+YoeoIoehEaeSmiu1IQs= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 split_huge_page_test can fail for the following reasons: 1. During the test, khugepaged may collapse previously split pages again, causing intermittent failures. 2. Since glibc commit 321e1fc73f (“malloc: Enable 2MB THP by default on AArch64”), glibc may call madvise(MADV_HUGEPAGE) for sufficiently large allocations made by memalign(). The underlying VMA may start at a different address from the aligned address returned by memalign(). Moreover, a subsequent madvise(MADV_HUGEPAGE) call does not split the VMA because it already has the same advice. This causes the test to fail because the check_huge_xxx() helpers incorrectly require the address returned by memalign() to match the VMA start address reported in /proc/self/smaps. Address these issues by applying MADV_NOHUGEPAGE after faulting in the huge page, preventing khugepaged from collapsing it again, and by replacing the use of /proc/self/smaps in the check_huge_xxx() helpers with /proc/self/pagemap and /proc/kpageflags. This patch based on v7.2 --- Yeoreum Yun (2): kselftest: mm: prevent random failure of huge page split for khugepaged kselftest: mm: replace usage of /proc/self/smaps for check_huge_xxx() helper tools/testing/selftests/mm/khugepaged.c | 26 ++--- tools/testing/selftests/mm/split_huge_page_test.c | 17 ++- tools/testing/selftests/mm/vm_util.c | 135 ++++++++++++++++++---- tools/testing/selftests/mm/vm_util.h | 1 + 4 files changed, 142 insertions(+), 37 deletions(-) --- base-commit: 8d3ae59288f1e7d58d76558a6ee96d533bc5019f change-id: 20260820-fix_split-f44939ec44b8 Best regards, -- Sincerely, Yeoreum Yun