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 4B48CC9832A for ; Tue, 29 Sep 2026 08:22:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5125D6B00B4; Tue, 29 Sep 2026 04:22:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4E95C6B00B5; Tue, 29 Sep 2026 04:22:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3FFFD6B00B6; Tue, 29 Sep 2026 04:22:02 -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 246776B00B4 for ; Tue, 29 Sep 2026 04:22:02 -0400 (EDT) Received: from smtpin14.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 96DF0C03E7 for ; Tue, 29 Sep 2026 08:22:01 +0000 (UTC) X-FDA: 85266106842.14.ED7E7DA Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf21.hostedemail.com (Postfix) with ESMTP id DDD3A1C0003 for ; Tue, 29 Sep 2026 08:21:59 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=c3HPnUQ4; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf21.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1790670119; 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=dudcfgQ+U80HosFEMLniY29B8GpEpDKgVLsTf9hVEyM=; b=Jm1uXCEoaNZAyVCV+BRgbyCUP9k60Yp44Qj40GjDMT/u0ZBN3ah0rfMWxZ/Q2ODp2tNFVU WfNM7s1DY+cjNsCBA54/dUjdQ1JVTDZsvShIzdW5BHJ3vakmKJhgP2UXRcKiiAeel2I4kK vZHy1bHz+ZlJQ8lOscRIxGCuVR0umz0= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=c3HPnUQ4; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf21.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790670119; b=k+WZpUwt6In3vkAQ3JONd/O8vj0vE3jKI/BcXn4+SaRn7znmwAQ6CWfKjPIZ05+NvILvcM Ka98qcd9ZOq4jWrkH/Ov+O+hmNLjpc3klce5d9vL/H2j9XTVQkUIUVucHZBJtD4jQ5/dBi ACnGz2c0sJ2VUrBeh5f1THY/G+au7NE= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 5D8B060A5E; Tue, 29 Sep 2026 08:21:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 62DC31F000FF; Tue, 29 Sep 2026 08:21:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790670119; bh=dudcfgQ+U80HosFEMLniY29B8GpEpDKgVLsTf9hVEyM=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=c3HPnUQ4tusSpEue14ve0rl76w3siWOCOiPWcL5/FLV4AFdvpjYu0xXJ5NNCZD7pD NYQWOH1kgMNMMMRLg8Mv6PmGN8gJgFDkFDDZUuuKp6mQeN7V3wTuXHqd4bNX0Fz79b k8iolFPyxXtwFm7OBUOqWKE7eZdpa7mNpU4cgBMcby4Z1e9nUp1dV+90Pv5Gbu1TW7 j76Mg9ZmkTq2qx3fVifjWqDWHJaUbJGs1xiT9nCR+SWSoSfixkzSIsfirRGNJ94pJ8 9g2JfDfcpb2kYeb8dhz1GWWSdU3syuePnM7IhaYRbGbW1R/PKedQyROCaA0n9gnARH OFczK3zNATd3g== Message-ID: <1246dd4e-b2a1-42e6-8fcf-7e6b2514cb87@kernel.org> Date: Tue, 29 Sep 2026 10:21:53 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/2] kselftest: mm: return fail when child test result is fail in khugepaged To: Yeoreum Yun , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Lorenzo Stoakes , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Shuah Khan References: <20260923-fix_khugepagd_fail-v3-0-b387e92fe1a9@arm.com> <20260923-fix_khugepagd_fail-v3-1-b387e92fe1a9@arm.com> 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: <20260923-fix_khugepagd_fail-v3-1-b387e92fe1a9@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: DDD3A1C0003 X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: x5zraanaug37joxghx9myfwf3imcag4d X-HE-Tag: 1790670119-289970 X-HE-Meta: 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 PSb2XReo jE2apJM1O1ytgLNvsm8HkfX/GT9w+SANnd5IxkeKXMRnIxhWQEm+zvNOm3U/2lqcGil4uyCL4XzVABpWgZtdK9vUISCpH+24bdg8kp2OoSfnO24oB/tWsYq3ddifO69Zlodeqw8JgHw70dOZDxFL9lP095cSdsspI5nF23tsPUDhqTrm7qc/Lp1am5mi/1QZlMBh9bAE8bn/Q6/1ZYMkNsM1O3csIqjqfYs7/nc8aPvqHIExe8qVGqxu3nyPhzv25zwWqX9Tz+CGUe2K3hgwK7lgKBE+Y3ctmPrSYy440IV5E/6NR+EX8ZOpdkBapK5rXHpFrfUWtxBPgFTc8zPymGxI1kV2a8Hqb2ZygEwF0FZPNGxxoccJv7T+MYmfNU64w4yJoWV270gnJkzI= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/23/26 17:29, Yeoreum Yun wrote: > Although the child process in collapse_fork*() or collapse_max_ptes_shared() > reports `KSFT_FAIL`, the result is ignored because the test only checks > whether the parent’s page was collapsed into a huge page. > > As a result, the test is considered successful whenever the parent’s page > is a huge page, even if the child test fails, as shown below: > > # > # Run test: collapse_max_ptes_shared (khugepaged:anon) > # Allocate huge page... OK > # Share huge page over fork()... OK > # Trigger CoW on page 1023 of 2048... OK > # Maybe collapse with max_ptes_shared exceeded.... OK > # Trigger CoW on page 1024 of 2048... Fail > Bail out! Unexpected huge page > # Planned tests != run tests (26 != 23) > # Totals: pass:23 fail:0 xfail:0 xpass:0 skip:0 error:0 // child failed. > # Check if parent still has huge page... OK // parent hpage success > ok 24 collapse_max_ptes_shared // considered as success > ... > # Totals: pass:26 fail:0 xfail:0 xpass:0 skip:0 error:0 > > To address this, propagate the child’s failure and skip the subsequent > check in the parent. > > Reviewed-by: Baolin Wang > Signed-off-by: Yeoreum Yun > --- That test implementation is rather messy ... :) Acked-by: David Hildenbrand (Arm) -- Cheers, David