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a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1777619647; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=3wuiBgrSnuNWFFf3R6F4ASDCg9n9Aja6Tcjd2kviias=; b=2Ny9YAg4T+B7O1s1KVv3KSRRFQMj04561wWr7iDRTXBn2pPMn50/lLqionHsOtKhrYfl0S ut7YxMLUM/5UDNCm1WgA3vnF1koFXTkWF+bNFU10ReG9YX6rB0hQI3oKBOhlWiKrjIdCRv qGx6h90/4rZa6wtPZnvjApOme92m+r0= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 1AADE6014C; Fri, 1 May 2026 07:14:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B5CCC2BCB7; Fri, 1 May 2026 07:14:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777619646; bh=cQmKPuqMrDemevQCdVHNG3pm0Jgypr9Bvlq0WQ6tW3s=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=hRMF90btORbLa2eELV9f7wF9G28pAwviSKeg8kf/SO8uAj0+IIjdK8sKON3mgyFXh WjzwYIPSLUb773zLJVMRTnk0nTFFvpH0Is6BH1NQSOZnH/17FKYxk912Vg/JUMOVPd xFiTD+pgaH2SYDDrGGdx9QQfyD1T8BUjrwKp1jSuZHYZaeUFcXDbfv8071teoUgRaT buiCiOAlgU+lRytCwntfFFqT/jCbX+OaLBNK/EYDIoRY3ui5ENCdlLEMDzGTT1djrS UgTU6VgOZqrRKwvSbY/KBY0bjVNXqn8a3lV9kphVuF4uXNiZrG1nuUkTqT9X5+FsrE gXLoE0XyJEjWg== Message-ID: <428786cf-6873-4cdf-ae57-cef43b174f8c@kernel.org> Date: Fri, 1 May 2026 09:14:01 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [00/45 RFC PATCH] 1GB superpageblock memory allocation To: Rik van Riel , linux-kernel@vger.kernel.org Cc: kernel-team@meta.com, linux-mm@kvack.org, willy@infradead.org, surenb@google.com, hannes@cmpxchg.org, ljs@kernel.org, ziy@nvidia.com, usama.arif@linux.dev References: <20260430202233.111010-1-riel@surriel.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: <20260430202233.111010-1-riel@surriel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: z9gaej7ak98yst8staezkgyocwkt3sk7 X-Rspam-User: X-Rspamd-Queue-Id: C1A4F180004 X-Rspamd-Server: rspam07 X-HE-Tag: 1777619647-20131 X-HE-Meta: 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 za3qMy5B jC+qWcrKwWW866Z9FZcKXxqDkJIMid58KoiauS6KxZl2X2MWVoUvNY4+AJ0TSSmKRFvj5vzDuqTVtyxLub79gdZqkYaXj7Abwvi2ar6VFFWG6i9Kq/NR8DS5W9sAYtRTMsMDs9NRapOlIN5+hMCcEsO3wa3QGMesKoEVF01FUj/pGJwFNln7ii2ej77pj5r4XorW89ZamFhdcOGiTRtsv38+e1FcaadUWmCjWUR0YqQKoZggT2MM5LyXVSNXGGyxXYMqr Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 4/30/26 22:20, Rik van Riel wrote: Is there some text missing here, given that the first paragraph starts with "Neither of those" and I am not sure which solutions you have in mind? > Neither of those are great solutions, given that modern servers > tend to be large, often run multiple workloads simultaneously, > and each workload wants something else. > > To address that issue, this patch series divides memory not just > into 2MB page blocks, but into PUD sized superpageblocks, and > aggressively tries to steer unmovable, reclaimable, and highatomic > allocations into those superpageblocks that have already been > "tainted" by such allocations. -- Cheers, David