From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794660192; b=WAOzuJTbZRyKDhYLbxO5x9OFtQmaeBWwZksN/e6JDomZTnTRuqemgE6iAjLO7xq0cXPy xSjeXsvTHeqnYc3v5ilcT/5HkKjD/C7C0mEb37UPEO9uHvFLxygFT1JX+z7Svkm3ZKltB ymVsxgvkwkNUkLUAsoD96ekfH3ilRfB2IwQaVtVkwSikXowPJ838bZUpmFADuX+cNA3kx xemCf01Ei8xf7jH282RLBzVdBhD+DMlHKsnOeaiP/BFSxU2TMeCWHriL1UGUOpPhZ2Ijm GJL/5qt4cm1OYD5naKHu/RIG09C05DOSk6FKMXQQHtzjWrLfTHWSBln5pXU/42uvBGQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794660192; h=DMARC-Filter:Received:Received:DKIM-Signature:Message-ID:Date: MIME-Version:User-Agent:Subject:To:Cc:References:Content-Language: From:In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=nLUYkZP6o3sE/c6t39+tiUT1HGJzvTdIPDTkJDNa1dk=; b=IEnvcfTsUI7LbkhyQxBsDjDb2vN4JKffTa7uC9MOG+kLytjSkRBzqbdwlG//DbG0Zb6C lSe0QGo3DfYGST39ay714JSSYZ+mOK9YcOunqxcSRIiHdpkSv5eFGDSdLHEJeVqfC8zKL RDXSTvgzyMGpvIbvhUBWK3NLu4r4u7b3EQrI0AwL2DucTEPjeIojZNEbD5pN+vZdEdAGq 6LB4enw8CPe1DK4zQ28VfkxEkY4mjCz29NNm2+/NRfMPteHeLGMbRowcsCPC01Ga68Bml 1oeDOraDUVBgInWnpOr4EeQro4Cn42kJ9gTj7pAIjX2NYPSJp5q8rZVBykuDIYmbDRA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=ii+NLzoq; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 22429606A323; Sat, 14 Nov 2026 12:43:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 22429606A323 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.a=rsa-sha256 header.s=foss header.b=ii+NLzoq 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 0F0171516; Sat, 14 Nov 2026 04:43:07 -0800 (PST) Received: from [10.163.159.227] (unknown [10.163.159.227]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 710D83F632; Sat, 14 Nov 2026 04:43:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1794660190; bh=UwozEJCLQAVoo0F8fItA/0T+tAX/hvIaLGcjA9Tmh10=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ii+NLzoqD8TWzkMaJ2vfWwCsnMLk/rchkW0O6KzWRKMDiXNGOjgpdl7+w/qnG84kO Irl9yb3tWZrzUFOcZ+3zjZeuZWkeaauZrDFVu+J1/en8ohB+gCiZCDOy10ir3R9IpY SRBHhLHb9B1wMIU18DhxaC02Cu28LnoCGTSiweJc= Message-ID: Date: Sat, 14 Nov 2026 18:13:00 +0530 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/4] selftests/mm: replace transhuge-stress with a THP compaction selftest To: Sarthak Sharma , Andrew Morton , David Hildenbrand Cc: Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Anshuman Khandual , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20261112090250.334344-1-sarthak.sharma@arm.com> Content-Language: en-US From: Dev Jain In-Reply-To: <20261112090250.334344-1-sarthak.sharma@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/11/26 2:32 pm, Sarthak Sharma wrote: > transhuge-stress is a stressor tool that repeatedly > allocates and splits THPs till a specified duration. If the > duration elapses, the test passes and fails only if a setup or > system call fails. > > This is not how a test residing in selftests/mm is supposed to > behave. So remove it and add a new functional test called > thp-compaction.c, that allocates THPs as much as it can, > splits those THPs keeping one page retained and discarding > others, and then retries allocating THPs, which will test > if THP compaction is working fine. If we are able to recover > more than half of the initial THPs, the test passes. Otherwise > it fails. > > This was suggested by David earlier [1]. > Isn't compaction_test.c already sort-of doing what you are trying to do here? > Patch 1 removes the current transhuge-stress. Patch 2 adds a check to see > if PFNs are being masked due to no CAP_SYS_ADMIN in the initial user namespace. > Patch 3 factors out THP split helpers from split_huge_page_test.c to vm_util.c. > Patch 4 adds the > new test. > > [1] https://lore.kernel.org/all/94ace42d-8d60-4475-953e-74fb3dc23774@kernel.org/ > > Sarthak Sharma (4): > selftests/mm: remove transhuge-stress > selftests/mm: detect masked PFNs in allocate_transhuge() > selftests/mm: factor out THP split helpers > selftests/mm: add a THP compaction selftest > > MAINTAINERS | 2 +- > tools/testing/selftests/mm/Makefile | 2 +- > tools/testing/selftests/mm/ksm_tests.c | 26 ++- > tools/testing/selftests/mm/run_vmtests.sh | 2 +- > .../selftests/mm/split_huge_page_test.c | 45 +--- > tools/testing/selftests/mm/thp-compaction.c | 215 ++++++++++++++++++ > tools/testing/selftests/mm/transhuge-stress.c | 146 ------------ > tools/testing/selftests/mm/vm_util.c | 65 ++++++ > tools/testing/selftests/mm/vm_util.h | 6 + > 9 files changed, 313 insertions(+), 196 deletions(-) > create mode 100644 tools/testing/selftests/mm/thp-compaction.c > delete mode 100644 tools/testing/selftests/mm/transhuge-stress.c >