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 AC2AE4915A5 for ; Wed, 9 Sep 2026 09:56:20 +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=1788947782; cv=none; b=XgheV269S8Mqb5m7AMAlEn3LMoJsPdRVLeeH/5evvTMPWq0JiWeDpL+n7lzpqNRKYxFLfq4rRU9DDaRXcyBPIBwjRkNSY3BTh1wKWGR72fsS1WlbggKL4W+ajzngYqo9FfkATd75CspC08S5at5FuBtOziaQJJ429kxZNOhciag= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788947782; c=relaxed/simple; bh=uf8D5m9HYTaZrc7d93WoJxgkkkji+vGtS3KIVwcx3cI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qYSp2cGaztLD8cO9tUGvGg7kcpOPrTRkq7bS3D4xZnn3OUQzjLv96CoF56tx/HzXJ9lJI+OF4Y9S1StCuOJxqkAHIyaZyJ+vj3pXuXW/m1f24jZG1pwKhmoaJzq/msjDKBmlfT5s5HUkvIoZsRmXBIeEWFQMAyw0b3B9e9yG33g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KNEgf5mw; 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="KNEgf5mw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 40CBA1F00A3D; Wed, 9 Sep 2026 09:56:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788947780; bh=ByKpa3vC0eC5ZuBtQYhI31h+rDqEMFcUW70pnZTcQhY=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=KNEgf5mwgM8CxhI5IANttxJV2blzsgGI6l5uqybUi5NYt6gaDzOWGl2Dg9RMMLgE5 fytqZ2nxAvUTdgQuLelPTbAZgc1XjHLNVTQ7pO1JuizKM/dc6XC+t1ev0Bcy1eQ63M 5IG4lis2yjJMRvwt1T0h8Dc2i12Y6VN8i8tvb5yi8diRdsf1gXGBHHTG4NPt2N0DpL POnHVDw2Mh620IUZOfsLcmFKY0/9+Z1Y3ghPiBj+VSXeewELZvZYmbgd1ituFFParz v+3CpC7sKI7vbMqle+Xq1s6dPpMnYsPe3uL54chp2Uyt78nzn6+e0pO8aLgSzzy+n2 lnVRnnXJsG9yw== Message-ID: Date: Wed, 9 Sep 2026 11:56:15 +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 09/17] mm/sparse: initialize memory sections earlier To: Muchun Song , Andrew Morton , Oscar Salvador Cc: Mike Rapoport , Vlastimil Babka , Lorenzo Stoakes , Michal Hocko , David Laight , "Liam R . Howlett" , Suren Baghdasaryan , Qi Zheng , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song References: <20260825084608.47437-1-songmuchun@bytedance.com> <20260825084608.47437-10-songmuchun@bytedance.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: <20260825084608.47437-10-songmuchun@bytedance.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/25/26 10:46, Muchun Song wrote: > Upcoming HugeTLB bootmem changes need sparsemem section metadata before > the HugeTLB bootmem allocation path runs. The memory sections are > initialized from sparse_init(), which is called too late for that setup. > > Move the code that initializes sparsemem section metadata for memblock > ranges into mm_core_init_early(), before free_area_init() and the HugeTLB > bootmem setup. Rename the helper to sparse_sections_init() so the new > caller describes the sparsemem-specific initialization step. > > This is a preparatory change. > > Signed-off-by: Muchun Song > Reviewed-by: Mike Rapoport (Microsoft) > --- > v5: > - Collect Reviewed-by from Mike Rapoport > > v2: > - Rename the helper to sparse_sections_init() to describe the section > metadata initialization (suggested by Mike Rapoport) > - Fix the !SPARSEMEM stub name so SPARSEMEM=n builds compile > (reported by Sashiko) > --- > mm/mm_init.c | 1 + > mm/sparse.c | 10 ++-------- > mm/sparse.h | 2 ++ > 3 files changed, 5 insertions(+), 8 deletions(-) > > diff --git a/mm/mm_init.c b/mm/mm_init.c > index 0317fb781e77..e2a16d833635 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -2642,6 +2642,7 @@ void __init mm_core_init_early(void) > { > kho_memory_init_early(); > > + sparse_sections_init(); > free_area_init(); > > hugetlb_cma_reserve(); > diff --git a/mm/sparse.c b/mm/sparse.c > index e6cb67ca9c8d..439802e6a6ad 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -191,12 +191,8 @@ static void __init memory_present(int nid, unsigned long start, unsigned long en > } > } > > -/* > - * Mark all memblocks as present using memory_present(). > - * This is a convenience function that is useful to mark all of the systems > - * memory as present during initialization. > - */ > -static void __init memblocks_present(void) > +/* Initialize memory section metadata for all system memory. */ I'd drop this comment, it's not entirely accurate. A lot more initialization of the sections happens later. What this function mostly does is (a) Allocate sparse-exteme metadata (b) Temporarily store the nid and mark the section for being present and online I have patches to get rid of __section_mark_present() and just set them all to SECTION_IS_EARLY|SECTION_IS_ONLINE such that we can just iterate early sections and get rid of that PRESENT monstrosity. Apart from that LGTM, even though I don't particularly enjoy splitting us now having two init entry points sparse_init and sparse_sections_init Where it's rather unclear from the name what is actually happening. -- Cheers, David