From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793371070; b=JmC3Uvt0p7OLJJlxcXqj3IdbAYFJ7VVheNR9+hLHLphAqVlUIIJ5B3O4foRSyWdDW1Pd X8D4vxQSPuEUWczA13YYm3GlGcnGqlvJSypgPgSLlQb28yV+TYPNZHTOO1dy02B4ecPMV EnNoen0p6w8U8tKlr6F5/O+R54MhgtWI6UzZB6CylZYXpwVctGu5gCPppl+ZOE1SO/fX4 juMX4ZKI9uxAzRT25Dxt3nbbltG+GrBe+mOjF/3RNTLTKuz5zFQpx+6JSE+TwVQ6ptEuK /33pygE8MufqX8GhxLM+o3bjOMGnLtK1YoaJyTL0ABTQYQ4Mw1ew1qg6lQWHA7139hw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793371070; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:Content-Language:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=uOYO1vBz1WqzK+TimXJTNpBfLu8OouAosUkHyHS7j4s=; b=GwH0+0VnbFL6CnwqXKR+KRNrLNs9/XyvkO/jl3bhHgkB8YMIJ3hqyC81NDL4yBkQtrWg 8oNF7bE8Z1dpjGux7oY2jo0PkeP0ul7FE9GWOJ/mOrbDM37/YN4IJWO+qxK8Qm7jSCNky JxrKjr+98yMQUTlIfBOK17BMLN8OIMp1/gWo3Fq6k1brEqB4hFOatopxnFKiMP+MBTMPj qiU4B/x/UdMlNb65UEWnNFQQxFeUNfO1VGoWtzfZm/wRYBMIVVOA5t3bJuA4NPeW9SVAK 57RZMpSKpRcKjsHLJjSR/imU4NQL/ZfUXqPktYW7vrMT5KNYWpr5GYyqmfR4v6qfZRg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bF6R9279; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C177606A31C; Fri, 30 Oct 2026 14:37:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bF6R9279 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D2651F000C1; Fri, 30 Oct 2026 14:37:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793371069; bh=uOYO1vBz1WqzK+TimXJTNpBfLu8OouAosUkHyHS7j4s=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=bF6R9279b9c55sZunVufqLbJNHVpGKBm16I1N1EhD57KVbpTTV97cgxt+5quNJxhU AcBv2r5idRTx7z1d4FGqoqjMWGKBamCpKhDD815Qf7MjJH/RyQMi6wtbUEjI+Fsxfq 3UPWRaoTnrvjcppPpHLTtmK6MyDUEJGw7p1LycATDtjCtqj00PRuPJe0iUvWnJfNPO 4g8WVSEbre0QpmAQvYNAoIamCH34o/q4qyIKgFfupjeNVbxFYvnpmk8SydELkXK1Ad sH7yssGm1jBtjQi2I9rF/OMf/8/uxLDf3DBU8L+pn4Pd+PaTpTSitw09zSvNi70Mtb +e+8QcJWIXVYg== Message-ID: <9af1202f-9fae-4cca-904a-0ba00d7e726d@kernel.org> Date: Fri, 30 Oct 2026 15:37:29 +0100 X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 00/47] mm: various (urgent?) fixes To: Chris Mason , Muhammad Usama Anjum , Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , "Lorenzo Stoakes (ARM)" , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , Matthew Wilcox , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Josef Bacik , stable@vger.kernel.org, Thadeu Lima de Souza Cascardo , Mani Tofigh , Samiullah Khawaja References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> <2f23dafc-43a5-47c9-a819-e696cda6fd44@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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/30/26 14:10, Chris Mason wrote: > > > On Fri, Oct 30, 2026, at 8:12 AM, Muhammad Usama Anjum wrote: >> On 30/10/2026 11:35 am, David Hildenbrand (Arm) wrote: >>> >>> >>> Thanks for the results. IIUC it's schbench that shows a possible regression. >>> >>> I would expect that no changes here really affect performance at all (neither >>> positively nor negatively). >>> >>> "mm/huge_memory: fix list corruption when deferred_split_scan() races with >>> deferred_split_folio()" fixes locking, but I wouldn't assume that this matters >>> at all for this benchmark. >>> >>> "fork: take mmap_lock before copying mm_struct" changes locking, but I also fail >>> to see how that would affect the benchmark. >>> >>> Maybe some code layout changes just affect some benchmark on some machines? >>> Because already seeing 10 improvements makes me wonder how that could possibly be. >>> >>> So I'll move forward with these fixes for now and see if we get more reports and >>> could identify actual problematic commits. >> >> Yes, these improvements/regression might be because of code movement and how it >> has affected the run time performance. Most importantly, these results show that >> there isn't any drastic affect on performance. These fixes are good to go. > > This schbench configuration is going to be really sensitive to process placement, and it > should be doing all of its memory allocations up front. I haven't done many schbench > runs on this type of hardware, but I'd agree this result shouldn't indicate a bigger lurking > regression anywhere. Thanks Chris and Usama! I'll respin a v3 shortly and get it into -next tomorrow (unless something really odd sticks out). -- Cheers, David