From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 D5DDB486645; Mon, 28 Sep 2026 08:53:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790585600; cv=none; b=P/yL9EyQOdV1oS3lZXTrA92pajcc2rQWJR6LZhhil7UhCrRi1qqK0N+bWtDg5Xx8FjhE1rG7twenzZ+uFEMj2vUDYq0HzDPuyYurxa4eYGSJ8rarhm55Z7Vj/M6nWnc64USLMpp5zFfzHlKwcJiT1dZNlUV0Ewj+Blk8yE/Yna4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790585600; c=relaxed/simple; bh=5n1dtj32Adn4Qa5M0TJ1gDSy3xIvXkTfZrFdJGjnqXY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=b1J2X0j58hfy8D26VbyHGH5gfmutdac4JHsxtLWxI63kfHlrK+nQO3foXlHcss14kfMTeeGkuqWuSJs7ISTWSCiEzs3kf66JSDZxELX8OXJjhVxqrIkUUpXGSFNW5QglfSofQkBMONIpKQieZbiNGolKrGqdePPOlhRhJLCpois= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ur5AWO7g; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ur5AWO7g" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 667411F000FF; Mon, 28 Sep 2026 08:53:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790585596; bh=oMRlamwZOS6UGMnR7RRChBxeZocxPHKpOSIJpnFzjdg=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=Ur5AWO7gR/EbdOkHyt0zSPjUSRWOvbKnLYxi2SIB6aa3Lw07eZbQcaaveO8dbyFIz DxgDdE8bYmMTQ4WUyFOsPLtcPgv8pFsJm0zacnNwDrh28AwA9Wg24MECYdP9hFx6UU GHMKZz50SFXq25g3V+T/EJTW5jrgDAkIXbHevcRV9nsvgJsPc/cenqrQXtcnrEhgRp 6ISbEj8RRVQ1c7Nursl4ntsqbuRirELzECvjuVl2L32LrD2kcSOc56KipX1QBUb6QV kSrBHlPE93sJHrOgFH78l4HvnLJfZz4NsP+Ally3Sxvx2ml3kJBBgbEyDc6rB5NqHE 5FLJsz2UFKDig== Message-ID: Date: Mon, 28 Sep 2026 10:53:09 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/mm: uffd-missing-wp: add GC related functionality test To: Martin Cracauer , akpm@linux-foundation.org, linux-mm@kvack.org Cc: ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, shuah@kernel.org, peterx@redhat.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org References: From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/28/26 05:26, Martin Cracauer wrote: > Add a test that asserts that functionality needed for generational > garbage collection works. Namely to implement a write barrier using > userfaultfd instead of using segmentation faults. The planned target > is the GC in SBCL. > > The real GC will initially fill heap pages by using on-demand loading > of pages from an image file, either via mmap(2) or using userfaultfd > to decompress a page read from an image file made from individually > compressed blocks. This test doesn't do that so that it needs no disk > I/O and no decompression library. Instead, a fault will be filled by > copying page content from prepared pages in the heap. > > Assisted-by: Anthropic:Opus-5.5 > Signed-off-by: Martin Cracauer > --- > tools/testing/selftests/mm/Makefile | 1 + > tools/testing/selftests/mm/uffd-missing-wp.c | 413 +++++++++++++++++++ > 2 files changed, 414 insertions(+) > create mode 100644 tools/testing/selftests/mm/uffd-missing-wp.c Isn't something like that a better fit for LTP? -- Cheers, David