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 849CACA5FA5 for ; Tue, 29 Sep 2026 08:33:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6382A6B0088; Tue, 29 Sep 2026 04:33:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5E8E16B0092; Tue, 29 Sep 2026 04:33:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4FEFD6B0098; Tue, 29 Sep 2026 04:33:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 2F9546B0088 for ; Tue, 29 Sep 2026 04:33:02 -0400 (EDT) Received: from smtpin24.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 9C69640445 for ; Tue, 29 Sep 2026 08:33:01 +0000 (UTC) X-FDA: 85266134562.24.8CE54D5 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf01.hostedemail.com (Postfix) with ESMTP id 0D75F40006 for ; Tue, 29 Sep 2026 08:32:59 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=omxEZyzD; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf01.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1790670780; 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=kWgQ7PY++KZOODIaGPn/6f7fWLLF6eJjFXK1cuplJqI=; b=3znNdlMxGuCp0SNLalQKnvTWtPbN+igrP0sk1142uROKk5tq5AregD4aWSTLkX/YByB0sT pCoVN/iexOubtv6iHKZUs9YDDSV/56JQwwMwqLI1f75B7h9pXXRza4ykmkpXemtkwYaILQ +RwEYcT2lUPvWOMO6u/K0vFelvxtXfg= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=omxEZyzD; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf01.hostedemail.com: domain of ljs@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=ljs@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790670780; b=ZAnxvRmI05S4wCIIb4Dghvlaqj3c36y2gt9Gv0OifqnigytE4ilWoLNN2SrQwKGZ2mLE/j xyXjrNJhxjUmSCaMoy2JyMpc+OvhQ+5Y6EVfiHSECO+3rX/EjK3E14g7OGO28lUoMlW4Wp 7kAjY52uvaAATydRxdd4wBb0echKDTU= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 93B8660A59; Tue, 29 Sep 2026 08:32:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 544F41F00893; Tue, 29 Sep 2026 08:32:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790670779; bh=kWgQ7PY++KZOODIaGPn/6f7fWLLF6eJjFXK1cuplJqI=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=omxEZyzDwbTL1f+vpJPwUGu5x3lHd9zjhTmd0ryL+3e6loQf5WiX5DwS1z7MMgsyv fTrf3/ndS/R0PA14bGgvxLxv0SbwcZNsewFfrnwsrqYHBqy4W7DgI2jh+g+Z2sBENM WSDsjjnimLufz3POC8dGk49KDEzfFrokBGbTqCXS/ue9RoO2fs0X5vM5rD+7AgxmWo 3+vGXK6ZoYpXJjs2G+5U7ZsfALTGTteeIsNzul6a9ZRdahZMLHcs8lXurzwnHnBx7U frDhAgEr6gdZO7mpoYJEyxvtlDGjveQPqybu+3A8RzsoRKomv8UXAycN5tiftu2R9D iPbBIn2flF0Ww== Date: Tue, 29 Sep 2026 09:32:50 +0100 From: "Lorenzo Stoakes (ARM)" To: "David Hildenbrand (Arm)" Cc: Yeoreum Yun , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , Shuah Khan Subject: Re: [PATCH v3 1/2] kselftest: mm: return fail when child test result is fail in khugepaged Message-ID: References: <20260923-fix_khugepagd_fail-v3-0-b387e92fe1a9@arm.com> <20260923-fix_khugepagd_fail-v3-1-b387e92fe1a9@arm.com> <1246dd4e-b2a1-42e6-8fcf-7e6b2514cb87@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1246dd4e-b2a1-42e6-8fcf-7e6b2514cb87@kernel.org> X-Rspamd-Queue-Id: 0D75F40006 X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: da8o7wjnbr8a7xo4cf1a99t63t6fx8ye X-HE-Tag: 1790670779-39385 X-HE-Meta: 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 O9vBOctx PQhJXeg+iJ+i82h35GHYy/o9k+NvrOfAJF7nJX0ahsxtg3Yp770zW+sn5uFLoX2zakdXYQEj/Het8CAVKVYPapmP0RXTdgBMEqaJYUskzGsT8slVHpBf5ljNygDakM/YYFj53sY+wHbi2Gq0EmcpvmS/v/yLEsMsu2Q0G0NTIR41NmhZYLZ3JFMoTKydWoxZlLFA/GieZGNHvbm4aCtiJam+uh5kRShawE2zWQMTu0q9SeEmanAKbXE4BUl0bBtQVCxdqDo9SntWt69ocEv3DTU35XgMF77bR8JtkD/fymz9tS50fZ/E1/biP+GySPvL2I2yYBzu6F7Avwj831yVAKAdVdmUQvWVcXp02aKaSVmKTA8YDuq+ahKTd/fcvaEa+N4K0 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Sep 29, 2026 at 10:21:53AM +0200, David Hildenbrand (Arm) wrote: > 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 ... :) Yeah, I wish we could just convert more and more tests to the harness. Makes everything easier...! > > Acked-by: David Hildenbrand (Arm) Patch LGTM so: Reviewed-by: Lorenzo Stoakes (ARM) > > -- > Cheers, > > David -- Cheers, Lorenzo