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 28D4743148D; Thu, 16 Jul 2026 14:40:57 +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=1784212859; cv=none; b=S38Rtl8ngW6oWWu0EYj5298AkwAIqmHlMHAEDGJ4+a8PRJcsO7wLxNn2WxheTYwXZ5v6n5/QQUjP8EzRE0hIQAUAvY671SsCANJGnJ/yKQyDTTbsTdOJvn5kG7gAs0zmyCvkuKFU4RgtuQRL3FbTzv2YDryXshmcVB4bNGgQDHA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784212859; c=relaxed/simple; bh=IT0hGWORNFdEOjvToY5i+9zZactYQeEyvVe0kxz5H2s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Y1JHZwqhszjnO5gU6OYGC4vp5zV9n5/31NRJLJTWzpLMhgM67SitluENi929RNQ8458QgmQQH3g4iHFiIoax+v2oL/fAtEO+8TLrCI5Y5E+YwUe13u0Wzr0kKVWyERi6ofLXJ/6PMNRX6ynLBLmMQerFcbVw7Ky67zGkC3IMTI0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kK9sWOex; 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="kK9sWOex" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D0DC1F000E9; Thu, 16 Jul 2026 14:40:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784212857; bh=avwfvqQvBuo4kJWama3zKcnrK2MiPJPDY+UL3bT0tcE=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=kK9sWOexAIu3PHE/vl+jtGi0muqtZYfbmbvglnEZqTqayzxospTi1EeEu0Daedt/8 03rsBOGFmSpKIvZ4gFsBYGqCQ2gi74RVAnD47YMK5DgUkv+MWJa3r1BAI8IO66vwIO H0Su0ifPrazwL7KOR6WRYVQMUml5pZDK9xOct3Jd2iaDymTQH/H8Vb2tIc5/aMC5H6 vsUl/hGhpYhZWw+q9D1aLS9Z4b4dQ4xy3ctQRFZ9iTYUtboKTDx6tqsNi7VXsn6Csk 85vdq4FHTE7lRa3LUfCYZ4R/je5keMvenwdi8UyLkCcpDUnfTpobllCzS7vXKlrh9U FCkJ/biDc/ZYA== Message-ID: Date: Thu, 16 Jul 2026 16:40:53 +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 v5 2/2] selftests/mm: add PAGEMAP_SCAN test for THP PMD holes To: Kiryl Shutsemau Cc: akpm@linux-foundation.org, usama.anjum@arm.com, peterx@redhat.com, liam@infradead.org, ljs@kernel.org, vbabka@kernel.org, jannh@google.com, pfalcato@suse.de, rppt@kernel.org, surenb@google.com, mhocko@suse.com, zenghui.yu@linux.dev, shuah@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, stable@vger.kernel.org, kernel-team@meta.com References: <20260715144234.442721-1-kirill@shutemov.name> <20260715144234.442721-3-kirill@shutemov.name> <714bdcbb-92cd-4dde-820c-e3761cbbaf07@kernel.org> 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 7/16/26 15:03, Kiryl Shutsemau wrote: > On Thu, Jul 16, 2026 at 01:25:22PM +0200, David Hildenbrand (Arm) wrote: >> >>> + /* Fast path: category_mask == return_mask == PAGE_IS_WRITTEN. */ >>> + ret = pagemap_ioctl(mem, hpage_size, regions, ARRAY_SIZE(regions), 0, 0, >>> + PAGE_IS_WRITTEN, 0, 0, PAGE_IS_WRITTEN); >>> + for (i = 0; ret > 0 && i < ret; i++) >>> + fast += LEN(regions[i]); >>> + >>> + /* Generic path: same query expressed via category_anyof_mask. */ >>> + ret = pagemap_ioctl(mem, hpage_size, regions, ARRAY_SIZE(regions), 0, 0, >>> + 0, PAGE_IS_WRITTEN, 0, PAGE_IS_WRITTEN); >>> + for (i = 0; ret > 0 && i < ret; i++) >>> + slow += LEN(regions[i]); >>> + >>> + ksft_test_result(fast == npages && slow == npages, >>> + "%s pmd-hole reported written by both paths (%ld, %ld of %d)\n", >>> + __func__, fast, slow, npages); >>> +out: >>> + wp_free(mem, hpage_size); >>> + munmap(area, 2 * hpage_size); >>> +} >> >> Sorry if I wasn't clear. I think unpopulated_thp_scan_test() can actually reuse >> bits of unpopulated_scan_test(). > > Ah. Make sense. > > Here's my take on this. Looks good? Yes, thanks! -- Cheers, David