From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 708F72D7DF1; Mon, 16 Mar 2026 14:44:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773672260; cv=none; b=kO10kMOWVvbhliIg1fyCngSCuCViDhT66vHGyRg9wBxnmJuW70K5ib5sU7wouhJ62HYCITOQQo+jXa9HkEHVJFRqFbQpKeDCOxuAx0O0k+fGoPCrNBq8FiyKB3Y9orIfMGCIUUJ9dfrA43uGqSDtCAwC0jFOgEnxhyBMBjWehUY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773672260; c=relaxed/simple; bh=RWDptXH394kez7vsWxAJNKfiKtyiFebfEXRYauFWPxI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KXOju+zUFFXlDZt/03PfHxw4Tzxd5FDUHqODCl6U4fjE8t/LjeFLcUzZ7d8v61PzvNAECrg4Bq6ylZVOEyojql1i6BX7br0b99l9Urd7xFVPt/Nw9Z1o16Ss8bA9+dzsajhzNBfLOQv+vDGSeFJjt2/6Wa2S6Zv6H5Ef33LHN6g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ptk4SxbE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ptk4SxbE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2AC9C19425; Mon, 16 Mar 2026 14:44:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773672260; bh=RWDptXH394kez7vsWxAJNKfiKtyiFebfEXRYauFWPxI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Ptk4SxbEo4/hvLxqc1tWPJDZbTxCRLIRsmnGkN8VQMVTkGr6+aCK1Gmqqj5BozWSN kYQPpn7kArWkvxepUN4mFOPeJ0jwMeYDhjYa67KOU/HrXR60iYkFxSZS93j4CEs+fV uttyyH7XuLlDkBbFKRPLYSwjhZP07y6PRSD8O1TYo2kSw0DzMH9h4RxEi9VSVNPVjw QZiZvabmugwgBKxxxH8W6SfJ6W3jaVQmwP82QUiS1xA9h/7XOJk57yRLiu9cyhY9qN xJWkPWqwULrWsTC6Q8/5uUJE4gHj0lRbXsvDMGlDZijYwyWUIeek8nfugLJrPfQ/US 1uwRM+y+EgKKA== Message-ID: Date: Mon, 16 Mar 2026 15:44:14 +0100 Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/mm: add THP sysfs interface test To: Breno Leitao , "Lorenzo Stoakes (Oracle)" Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, kernel-team@meta.com References: <20260309-thp_selftest_v2-v1-1-a00cef41da44@debian.org> <9cb63c24-eaff-4954-97d5-2a422a0401fc@lucifer.local> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/16/26 14:47, Breno Leitao wrote: > On Mon, Mar 16, 2026 at 12:55:13PM +0000, Lorenzo Stoakes (Oracle) wrote: >> On Mon, Mar 09, 2026 at 05:00:34AM -0700, Breno Leitao wrote: >>> Add a shell-based selftest that exercises the full set of THP sysfs >>> knobs: enabled (global and per-size anon), defrag, use_zero_page, >>> hpage_pmd_size, shmem_enabled (global and per-size), shrink_underused, >>> khugepaged/ tunables, and per-size stats files. >>> >>> Each writable knob is tested for valid writes, invalid-input rejection, >>> idempotent writes, and mode transitions where applicable. All original >>> values are saved before testing and restored afterwards. >>> >>> The test uses the kselftest KTAP framework (ktap_helpers.sh) for >>> structured TAP 13 output, making results parseable by the kselftest >>> harness. The test plan is printed at the end since the number of test >>> points is dynamic (depends on available hugepage sizes and sysfs files). >>> >>> This is particularly useful for validating the refactoring of >>> enabled_store() and anon_enabled_store() to use sysfs_match_string() >>> and the new change_enabled()/change_anon_orders() helpers. >>> >>> Signed-off-by: Breno Leitao >> >> The test is broken locally for me, returning error code 127. >> >> I do appreciate the effort here, so I'm sorry to push back negatively, but I >> feel a bash script here is pretty janky, and frankly if any of these interfaces >> were as broken as this it'd be a major failure that would surely get picked up >> far sooner elsewhere. >> >> So while I think this might be useful as a local test for your sysfs interface >> changes, I don't think this is really suited to the mm selftests. > > That is totally fine. This test is what I have been using to test the > changes, and I decide to share it in case someone find it useful. > > Let's drop it. Out of interest, to we know why the test is failing for Lorenzo? I agree that the test is a bit excessive, in particular when it comes to invalid/idempotent values etc. I could see some value for testing whether setting the modes keeps working, but also then I wonder if that is really something we'll be changing frequently (and that breaks easily). -- Cheers, David