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 8B19C3D8122; Mon, 14 Sep 2026 14:08:17 +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=1789394900; cv=none; b=GDEBk6oAjI3b5yafBnzHyo6FdHOOEfEJDal8DZelxYHOZ4/4vcZt0s3hv0LfcoiSWEkAaNMcTCRYSwz7la1OJX64cyp5xJ4kgnRig8L2btZExnW67feXn4G5zRsMP/KOwYHO4clvTH8W/XnUqXkUMgAJRLKkDrt/bIvazBCe9hM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789394900; c=relaxed/simple; bh=QbMoY0kbPygeeQy0FJU1Cj2La8CunPtMn2ln+8667cw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hrNJ0nEpAS27lVxeSfQa4YNXf+mvwdhiPsOR7X/uYyQFEnklnUM2MYCdqr0SRrkpoHw63b0Ab+g6mIPU68xC0E7+kNEygGxFeeazqmy3erTHzDBded5bdO8CgaHCqy9z0nOojAL17vd1dEfU6+pdZhLGXFH2vNorp9rEKukRAdE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Yc6puxwy; 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="Yc6puxwy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0828A1F000FF; Mon, 14 Sep 2026 14:08:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789394895; bh=k1MgQ4YkjRCW7c7SjK50zV8Sm2h6ALPWZtu7yelOo0s=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=Yc6puxwy6rANj0lip7bIhBodmX1qJbjM7I+eZjazdFIQgAemi/LuQ/7RNRagtnNYA kL/jlNMvO0jZZrmkjZPX1AvXnzQrWtFRMkeMrp+JxEZ3hI0sd+/5uBronsBq3KPWNp ccFHv2YRryjKhdQe2NNuGHsKZnZV4qc+g1yWE+sfNKT32zVC/pZqOI7UNqvqlCeJRH Ch1W0FCUb21LyLByzEO2iQZwQPorZmXrlsdBknrOviWNrA+vaLvetPBWqP/rcVPTmm Pc/JZzqv1Sws6ZkzQF9W/qkTOKyUeuh+cSMn3d0JraAGtN+iuO/RXRmrJEPzds6d1n mKxTDI+qlHl/w== Message-ID: <08d3313b-d891-4202-b460-c5cefa96bbce@kernel.org> Date: Mon, 14 Sep 2026 16:08:03 +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 v3 2/3] kselftest: mm: remove HPAGE_SIZE and HPAGE_SHIFT macro To: Yeoreum Yun , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Peter Xu , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Shuah Khan , Jason Gunthorpe , Leon Romanovsky , Sarthak Sharma References: <20260914-fix_hpage_macro-v3-0-c9a305a01d39@arm.com> <20260914-fix_hpage_macro-v3-2-c9a305a01d39@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260914-fix_hpage_macro-v3-2-c9a305a01d39@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/14/26 09:30, Yeoreum Yun wrote: > HPAGE_SIZE and HPAGE_SHIFT macro is written based on the 4KB PAGE_SIZE. > When this macro is used in some test, test result would be strange in > the system where PAGE_SIZE is more then 4KB. > > Here is the example with transhuge-stress test with 16KB PAGE_SIZE: > > transhuge-stress: allocate 61073 transhuge pages, using 122146 MiB virtual memory and 1908 MiB of ram > 3.292 s/loop, 0.054 ms/page, 37106.002 MiB/s 2566 succeed, 58507 failed, 2566 different pages > 0.591 s/loop, 0.010 ms/page, 206850.792 MiB/s 0 succeed, 61073 failed, 0 different pages > 0.527 s/loop, 0.009 ms/page, 231895.107 MiB/s 0 succeed, 61073 failed, 0 different pages > 0.527 s/loop, 0.009 ms/page, 231839.704 MiB/s 0 succeed, 61073 failed, 0 different pages > 0.528 s/loop, 0.009 ms/page, 231544.782 MiB/s 0 succeed, 61073 failed, 0 different pages > 0.528 s/loop, 0.009 ms/page, 231462.074 MiB/s 0 succeed, 61073 failed, 0 different pages > 0.527 s/loop, 0.009 ms/page, 231770.300 MiB/s 0 succeed, 61073 failed, 0 different pages > ... > ok 1 Completed > > Remove the HPAGE_SIZE and HPAGE_SHIFT macro and introduce pmd_pshift() > helper to get the HPAGE_SHIFT properly. For HPAGE_SIZE, use pre-existing > helper, pmd_psize(). > > Also, run the KSM_MERGE_TIME_HUGE_PAGES test with a size of 512 MiB, > which is the least common multiple of the PMD sizes for 4 KiB, 16 KiB, > and 64 KiB base pages. Since allocate_transhuge() allocates mappings in > PMD-sized units, the test may fail with the previous size of 100 MiB, > which is not a multiple of the PMD size when the base page size is > 16 KiB or 64 KiB. > > After this patch, output of transhuge-stress: > > transhuge-stress: allocate 3817 transhuge pages, using 122146 MiB virtual memory and 119 MiB of ram > 2.558 s/loop, 0.670 ms/page, 47755.759 MiB/s 2585 succeed, 1232 failed, 2585 different pages > 2.640 s/loop, 0.692 ms/page, 46268.432 MiB/s 2585 succeed, 1232 failed, 2585 different pages > 2.635 s/loop, 0.690 ms/page, 46360.298 MiB/s 2585 succeed, 1232 failed, 2585 different pages > 2.782 s/loop, 0.729 ms/page, 43899.795 MiB/s 2616 succeed, 1201 failed, 2616 different pages > 2.692 s/loop, 0.705 ms/page, 45380.876 MiB/s 2627 succeed, 1190 failed, 2627 different pages > 2.612 s/loop, 0.684 ms/page, 46765.812 MiB/s 2628 succeed, 1189 failed, 2628 different pages > 2.683 s/loop, 0.703 ms/page, 45520.990 MiB/s 2630 succeed, 1187 failed, 2630 different pages > 2.727 s/loop, 0.714 ms/page, 44789.321 MiB/s 2631 succeed, 1186 failed, 2631 different pages > ... > ok 1 Completed > > Suggested-by: Lorenzo Stoakes (ARM) > Signed-off-by: Yeoreum Yun > --- [...] > index e712a980851c..fd1432dc6152 100644 > --- a/tools/testing/selftests/mm/vm_util.c > +++ b/tools/testing/selftests/mm/vm_util.c > @@ -21,6 +21,8 @@ > > unsigned int __page_size; > unsigned int __page_shift; > +uint64_t __pmd_psize; > +uint64_t __pmd_pshift; > > uint64_t pagemap_get_entry(int fd, char *start) > { > @@ -161,6 +163,9 @@ uint64_t pmd_psize(void) > char buf[20]; > ssize_t num_read; > > + if (__pmd_psize) > + return __pmd_psize; The only suboptmial thing about these functions is that we keep querying repeatedly in case of failure. If it failed once, it will fail always. You could either add a new variable for "queried" or encode it in the variables like uint64_t __pmd_psize = -1ull; uint64_t __pmd_pshift = -1ull; To then set them to 0 or the actual value after we queried. -- Cheers, David