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 B4F9E37475B; Thu, 10 Sep 2026 14:30:54 +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=1789050656; cv=none; b=c6j1P2zifJgfMN4H4cIe4Co/RWR3kv+N1xR9tCnDmG1xYNbHEeiAav8hf66St1XW1V/pL9M7CSSUsTuundqBZiXTPUl68Y/PCN/d/yJfGul1iBt+rVsejwl6+n1E9rmMlfRMf/2mx7xQQoubE4W3MIng4vfyLl8jQmOtwo7KooY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789050656; c=relaxed/simple; bh=3Rp1Gro0hOzX3FtSWUHW9R30sxNTX0x2CooV/G8FxVA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Q7hDudy0Az4kb10DhVbw0MssB+imWu/9gm//BOuCgJfny+vHOknkMXfi83qSwRPzy4AWDQAvDvGRV1J5rNYKpx8N7ZFWjlYo0KQJ+JTkOuuwVTnZLaXW3OT4+K6fMPTe52dWCxXl5/bmgD8GmAIMLXjPsisbfjKhVQZ9XV1oS9o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=C+NhKwxf; 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="C+NhKwxf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F14821F000FF; Thu, 10 Sep 2026 14:30:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789050654; bh=QYIjJzkgNcf/L8IdAlVc5CxNGSBjCKsHUzlpJK8zVLA=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=C+NhKwxftOndxbZynkT9flhdKmqwHy/1toG1XLj2OU1G58MCD12nAwLOIhGGZffUa AkRl65KSKyX9avFrOtHTOShpKJiVFO9OWw540xAJW2ldjVX8bahRSaXcbakvPiVE6X xQWEzmmDV5MP+RSKvhFEVX9A7FZ1YcY5WhB2lJtnnzuBMg2yd2/1mhk38AseGdM4h1 BEJEdyGAeJlI/33+zLCOswq8O/T611SDkNYOyWXz0THnaju4i0LucLbGX650EmuqTs TGVNI7c+s3GZAxvObikqWisVQNc/Wtqeh8KoI54CTVf9iO1E55s1tLKKFsBF7Dfnhn u2oqY5ERBi/0w== Message-ID: <44f7ce5c-b75c-4c44-9202-1d2d3a1de965@kernel.org> Date: Thu, 10 Sep 2026 16:30:43 +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 02/12] mm/sparse: refactor sparse_sections_init() To: "Lorenzo Stoakes (ARM)" Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , Brendan Jackman , Johannes Weiner , Zi Yan , Oscar Salvador , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Jan Kiszka , Kieran Bingham , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-cxl@vger.kernel.org, driver-core@lists.linux.dev, linux-fsdevel@vger.kernel.org References: <20260909-b4-sparsemem_cleanups-v1-0-008fc8d579fe@kernel.org> <20260909-b4-sparsemem_cleanups-v1-2-008fc8d579fe@kernel.org> 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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/10/26 15:29, Lorenzo Stoakes (ARM) wrote: > On Wed, Sep 09, 2026 at 03:32:55PM +0200, David Hildenbrand (Arm) wrote: >> memory_present() really identifies+prepares all early sections so the >> initialization in sparse_init() can properly iterating them to >> initialize metadata. >> >> Let's just inline memory_present() into sparse_sections_init() and >> cleaning up the code a bit while at it: make it clear that we are operating >> on pfns. >> >> Note that we call set_section_nid() now only if the section >> was not already created earlier. Now, there is no more inconsistency >> between what we (temporarily) store in ms->section_mem_map and what >> we store in our section->nid array. >> >> Signed-off-by: David Hildenbrand (Arm) > > In general please keep move/refactor steps separate. It makes it harder to > review when two things are going on at one time. > > But I guess in this case the diff wouldn't be that different. Yeah, I actually want back and forth here and decided to keep it simple. > > Anyway seems reasonable so: > > Acked-by: Lorenzo Stoakes (ARM) Thanks! > >> --- >> mm/sparse.c | 41 +++++++++++++++++------------------------ >> 1 file changed, 17 insertions(+), 24 deletions(-) >> >> diff --git a/mm/sparse.c b/mm/sparse.c >> index 6a6d258862904..36e3d854febc5 100644 >> --- a/mm/sparse.c >> +++ b/mm/sparse.c >> @@ -179,22 +179,27 @@ static inline unsigned long first_present_section_nr(void) >> return next_present_section_nr(-1); >> } >> >> -/* Record a memory area against a node. */ >> -static void __init memory_present(int nid, unsigned long start, unsigned long end) >> +void __init sparse_sections_init(void) >> { >> - unsigned long pfn; >> + unsigned long pfn, start_pfn, end_pfn; >> + int i, nid; >> + >> + sparse_extreme_init(); >> >> - start &= PAGE_SECTION_MASK; >> - mminit_validate_memmodel_limits(&start, &end); >> - for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) { >> - unsigned long section_nr = pfn_to_section_nr(pfn); >> - struct mem_section *ms; >> + for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) { >> + start_pfn &= PAGE_SECTION_MASK; >> + mminit_validate_memmodel_limits(&start_pfn, &end_pfn); >> >> - sparse_index_init(section_nr, nid); >> - set_section_nid(section_nr, nid); >> + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { >> + unsigned long section_nr = pfn_to_section_nr(pfn); >> + struct mem_section *ms; >> >> - ms = __nr_to_section(section_nr); >> - if (!ms->section_mem_map) { >> + sparse_index_init(section_nr, nid); >> + ms = __nr_to_section(section_nr); >> + if (ms->section_mem_map) >> + continue; >> + >> + set_section_nid(section_nr, nid); > > So the main change seems to be calling set_section_nid() only if > !ms->section_mem_map (and obv. calculating ms earlier), as described in the > commit msg. Yes! I also played with having that in a standalone patch but judged that it's not really worth it. I can move it to a separate patch if you think it would be better! -- Cheers, David