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 89C412E6106; Thu, 14 Aug 2025 11:45:50 +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=1755171950; cv=none; b=MEcGBj3Mr5mIdnbIUwOaVdMtU/HfbLubPs0LN2znD7CTpER69cAD/wup4l34h2uSIf9JGv3xyeqVAcLI5AeNH3b5FJRXwT6IjPsK5oCKzCr3j/6iqTpHves4eCG1md6y33LZAe393YVeO28iTgtEmUyOgFEGukp2pp2nEfjpzKw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755171950; c=relaxed/simple; bh=FexkV7nvaMJKSQuSjt56VRn1ropgn6XWofqYu3VqSl0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bx1mkDSspXgCilokvH8kPICDDpkmIB5ifWSSyueAnBaXmftSTYYxPjdKOz8RsAJvhE6dxjseVgAs3sSq+KcDxavje/uHUZ5hnMTeVn31lg+LA8Oqhaf/5Gzwi7QsUgUMEo7KwElEdJ4vWDKrel6qlMJW7vc4tPLB/EZRtcy5HI8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OPnGEXsm; 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="OPnGEXsm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6900C4CEF1; Thu, 14 Aug 2025 11:45:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755171950; bh=FexkV7nvaMJKSQuSjt56VRn1ropgn6XWofqYu3VqSl0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OPnGEXsmQefCR5XKxWgB20+CdEPRHLpwVjZ9QqpgyiEZ/0tCDnmajIc2xnznI+BzQ Is37m5tR5w39ME0RZCAMaBBsKQRSYqMs9a9tZjjyQriX3RqQOr5IihltzPkGu3m3Q4 vZTJUJH1TKkWTXuh5TamQ5xvr35SXOixpW9FVi2OiCGYyXHmfuOj0dXi7B8UQAC5Q+ zxQk6CKRtdavLtwGvB7gY6HSlp4w30N0rA/eF4w9gIis1iaNFxzbmJZsXiOQE7bHUr 9ZJMetEeDzQbchb9v2/vyLtoHZnblpw/SncrzFzAA5/Uj9OF05Wi8okNIKcTLXJXu5 tNIXry1AK4ePw== Date: Thu, 14 Aug 2025 12:45:42 +0100 From: Mark Brown To: Lorenzo Stoakes Cc: David Hildenbrand , Usama Arif , Andrew Morton , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, corbet@lwn.net, rppt@kernel.org, surenb@google.com, mhocko@suse.com, hannes@cmpxchg.org, baohua@kernel.org, shakeel.butt@linux.dev, riel@surriel.com, ziy@nvidia.com, laoar.shao@gmail.com, dev.jain@arm.com, baolin.wang@linux.alibaba.com, npache@redhat.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, vbabka@suse.cz, jannh@google.com, Arnd Bergmann , sj@kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH v4 7/7] selftests: prctl: introduce tests for disabling THPs except for madvise Message-ID: References: <20250813135642.1986480-1-usamaarif642@gmail.com> <20250813135642.1986480-8-usamaarif642@gmail.com> <13220ee2-d767-4133-9ef8-780fa165bbeb@lucifer.local> <5b341172-5082-4df4-8264-e38a01f7c7d7@lucifer.local> <0b7543dd-4621-432c-9185-874963e8a6af@redhat.com> <5dce29cc-3fad-416f-844d-d40c9a089a5f@lucifer.local> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="HgKF1GOS9//9I841" Content-Disposition: inline In-Reply-To: <5dce29cc-3fad-416f-844d-d40c9a089a5f@lucifer.local> X-Cookie: This sentence no verb. --HgKF1GOS9//9I841 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Aug 14, 2025 at 11:49:15AM +0100, Lorenzo Stoakes wrote: > On Thu, Aug 14, 2025 at 11:32:55AM +0200, David Hildenbrand wrote: > > On 13.08.25 20:52, Lorenzo Stoakes wrote: > > > I can't see anything in the kernel to #ifdef it out so I suppose you mean > > > running these tests on an older kernel? ... > > > But this is an unsupported way of running self-tests, they are tied to the > > > kernel version in which they reside, and test that specific version. > > > Unless I'm missing something here? > > I remember we allow for a bit of flexibility when it is simple to handle. > > Is that documented somewhere? > Not sure if it's documented, but it'd make testing extremely egregious if > you had to consider all of the possible kernels and interactions and etc. > I think it's 'if it happens to work then fine' but otherwise it is expected > that the tests match the kernel. > It's also very neat that with a revision you get a set of (hopefully) > working tests for that revision :) Some people do try to run the selftests with older kernels, they're trying to get better coverage for the stables. For a lot of areas the skipping falls out natually since there's some optionality (so even with the same kernel version you might not have the feature in the running kernel) or it's a new API which has a discovery mechanism in the ABI anyway. OTOH some areas have been actively hostile to the idea of running on older kernels so there are things that do break when you try. TBH so long as the tests don't crash the system or something people are probably just going to ignore any tests that have never passed. --HgKF1GOS9//9I841 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmidzGUACgkQJNaLcl1U h9A7uAf/TsWdfXYkIPkM2Rj3C1HzjIuj6j4nnUhMESgtZSbf9Am99POGQmQxnUay Mz75k34/LOlxbUGyk2oz2tqb4Ad725WPmSqg4IEQXJ3or551O2tAApBrrbwTKfrT ha9jUqj/hhFasDuM9PZsHTUcEk4DKGYtFHOtrucuQMDOSNH7lsB3BEVyaY4xxHzM d2dWm3i1c8VlbU8gFIX794INH1sdcja2Syh0d5wraBAZ+NS+uJ5iWyZw43YgTGiX qQR+HWxD/m3NSNX6L58jpZYJq6Q40xDz8aQQiAd2omnwIYWln4HIitcYTpeNvQNw Poh6lZXtgIVoXt2Io6PYJpr3LnpP6A== =Xem/ -----END PGP SIGNATURE----- --HgKF1GOS9//9I841--