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(p200300d82f1bb8006fdb1af24fbd1fdf.dip0.t-ipconnect.de. [2003:d8:2f1b:b800:6fdb:1af2:4fbd:1fdf]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-450d7f8eceasm200932785e9.7.2025.06.04.06.30.05 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Jun 2025 06:30:06 -0700 (PDT) Message-ID: <8abecd5b-2768-49d0-afc3-561b95d77a24@redhat.com> Date: Wed, 4 Jun 2025 15:30:05 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 1/5] drivers/base/node: Optimize memory block registration to reduce boot time To: Donet Tom , Andrew Morton Cc: Mike Rapoport , Oscar Salvador , Zi Yan , Greg Kroah-Hartman , Ritesh Harjani , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Rafael J . Wysocki" , Danilo Krummrich , Jonathan Cameron , Alison Schofield , Yury Norov , Dave Jiang , Madhavan Srinivasan , Nilay Shroff , linuxppc-dev@lists.ozlabs.org References: <2a0a05c2dffc62a742bf1dd030098be4ce99be28.1748452241.git.donettom@linux.ibm.com> <20250603200729.b7581e017e4ca63f502c795e@linux-foundation.org> <9f7ae0e6-4640-418d-a4db-dba594377ac2@linux.ibm.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <9f7ae0e6-4640-418d-a4db-dba594377ac2@linux.ibm.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: sC2aOt6u6WC2PVU902XxLiS_fl-x9UvkWiTvgKyIlE4_1749043807 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspam-User: X-Stat-Signature: im6k8hcgah63g3q4797waatn9mhamawf X-Rspamd-Queue-Id: A201840015 X-Rspamd-Server: rspam11 X-HE-Tag: 1749043810-51337 X-HE-Meta: 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 j1XFPfMM 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 04.06.25 15:17, Donet Tom wrote: > > On 6/4/25 3:15 PM, David Hildenbrand wrote: >> On 04.06.25 05:07, Andrew Morton wrote: >>> On Wed, 28 May 2025 12:18:00 -0500 Donet Tom >>> wrote: >>> >>>> During node device initialization, `memory blocks` are registered under >>>> each NUMA node. The `memory blocks` to be registered are identified >>>> using >>>> the node’s start and end PFNs, which are obtained from the node's >>>> pg_data >>> >>> It's quite unconventional to omit the [0/N] changelog.  This omission >>> somewhat messed up my processes so I added a one-liner to this. >>> >> >> Yeah, I was assuming that I simply did not get cc'ed on the cover >> letter, but there is actually none. >> >> Donet please add that in the future. git can do this using >> --cover-letter. > > Sure, > > I will add cover letter in next revision. > > >> >>>> >>>> ... >>>> >>>> Test Results on My system with 32TB RAM >>>> ======================================= >>>> 1. Boot time with CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled. >>>> >>>> Without this patch >>>> ------------------ >>>> Startup finished in 1min 16.528s (kernel) >>>> >>>> With this patch >>>> --------------- >>>> Startup finished in 17.236s (kernel) - 78% Improvement >>> >>> Well someone is in for a nice surprise. >>> >>>> 2. Boot time with CONFIG_DEFERRED_STRUCT_PAGE_INIT disabled. >>>> >>>> Without this patch >>>> ------------------ >>>> Startup finished in 28.320s (kernel) >>> >>> what.  CONFIG_DEFERRED_STRUCT_PAGE_INIT is supposed to make bootup >>> faster. >> >> Right, that's weird. Especially that it is still slower after these >> changes. >> >> CONFIG_DEFERRED_STRUCT_PAGE_INIT should be initializing in parallel >> which ... should be faster. >> >> @Donet, how many CPUs and nodes does your system have? Can you >> identify what is taking longer than without >> CONFIG_DEFERRED_STRUCT_PAGE_INIT? > > > > My system has, > > CPU      - 1528 Holy cow. Pure speculation: are we parallelizing *too much* ? :) That's ~95 CPUs per node on average. Staring at deferred_init_memmap(), we do have max_threads = deferred_page_init_max_threads(cpumask); And that calls cpumask_weight(), essentially using all CPUs on the node. ... not sure what exactly happens if there are no CPUs for a node. > Node     - 16 Are any of these memory-less? > Memory - 31TB -- Cheers, David / dhildenb