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 E082E3C5529; Wed, 18 Mar 2026 11:32:17 +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=1773833538; cv=none; b=ufJbJwXqUC0erJAol4GWWYRR0iZjsWtlntNzWsyX6OskX0+GAE0/nFTMsxo221I/url0z2vetxzt9ZqxjEraVeRW4JHv6RKpXftztfdkP5T0VRkYou4ceYvaooPuMtkNIRCYdeeoLv9oj6o+s8ekGX2U8+oZW/s5P51dJfu/KGo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773833538; c=relaxed/simple; bh=R//hRNxAoqWyABoXCwcHk7g7S0ZjvnmQaJYFCwkVb3M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PBC2Gmzeuk/KW/NRgMKYPUMxMYRAvBnWFhtx/rqGHgjLTDgSC5oPTX2wB6c47RPonu0+G9JRygWEcq5nXOB47/V/ug89JAtGcJf6ba08S7iM7sw1IhLLIRRqSm1DNeUTg6stbHxwfFfRfrkb8xEz9JLXJC+w21+0hxBruC+SE8c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=W5jM9K95; 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="W5jM9K95" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B008C2BCB4; Wed, 18 Mar 2026 11:32:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773833537; bh=R//hRNxAoqWyABoXCwcHk7g7S0ZjvnmQaJYFCwkVb3M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=W5jM9K95/DWUgYu5hZ+3p6ju4Ia4B7o5b9j30H6XgD6UoSIvS/lTsTypNXXToZ6OF wtYxJ1mqPlFEp3qPt6cnv1+m+TaYK80euQ7i7TB1WFDU5L0QUy1WJ96ydPXcCQGdHu AID/65D6nRppq07Vr3DknUSXuGve8NHQK8m47isO5RudZObvJbqfae8VkMVLl4tUTg vyUSYUR/IOjG7gV/uz9je96K2vXsBSGh46x1fBCWakynXRo/DP/dWVRHlwXtYXRNHF BpJFsJafe0rDG/AHvUt2CzARvRGz9EaVQ42yasLMqKV7I0wnPeOhyxO99+QGoQkIEJ RKnBrwEYsXg+w== Date: Wed, 18 Mar 2026 11:32:10 +0000 From: "Lorenzo Stoakes (Oracle)" To: Chunyu Hu Cc: Andrew Morton , david@kernel.org, shuah@kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev Subject: Re: [PATCH v3 0/5] selftests/mm: skip several tests when thp is not available Message-ID: <893e70b9-1ed2-419b-9079-5b397b2cec54@lucifer.local> References: <20260317094419.1429259-1-chuhu@redhat.com> <20260317113730.45d5cef4ba84be4df631677f@linux-foundation.org> 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=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Mar 18, 2026 at 05:22:40PM +0800, Chunyu Hu wrote: > For question one. In guard-region test, collapse tests are for checking > collapse is denied when operating on guard region, not for checking > madvise(MADV_COLLAPSE) will fail when thp is setup to 'never with sysfs, No, if thp is set to never, madvise(MADV_COLLAPSE) still succeeds. This is a source of confusion for many :) > result is same, but it's a different test. Maybe we don't have strong > interest to test when thp is set to 'never' in this collapse test. > Do you perfer we let it run when thp is setup with 'never'? Yes because it should still function then :) Cheers, Lorenzo