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b=ot0TX+03yOgzXrp8V7VE9CTLkYrkd0ZBlLgBbzx8SovkOxfR8IJChQWDsXmPsJcIH yUuy6/rCRZHxamblQ217ZHj1seYnsi1jdhHzJU8HR2QNJgJbuGbb6vxLx5B+8Hgs5Z v7lzYET7aRBhNj0yL1kz7VrcnGdSmYYf3Vzit6lWUVXAfYdqJ9GMKcio+8D1S6n2Os Qn25r5M9g94b5zudlxshPinbuuabMmzLeM1lJJWXluq0lUtJTBnaynQ9gFATakZN5H sYfzw3/dGyKrzU+JhcgzHVkL/S9aG6JvP2AEUotwxX9/6/mKI9UrKHbh64kevzHXPf 2DjJHK2bGFBZw== Message-ID: <44b12ede-1e16-47f5-9051-27fa4ea34236@kernel.org> Date: Fri, 5 Jun 2026 19:49:34 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH mm-unstable v19 12/14] mm/khugepaged: avoid unnecessary mTHP collapse attempts To: Nico Pache , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Cc: aarcange@redhat.com, akpm@linux-foundation.org, anshuman.khandual@arm.com, apopple@nvidia.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, byungchul@sk.com, catalin.marinas@arm.com, cl@gentwo.org, corbet@lwn.net, dave.hansen@linux.intel.com, dev.jain@arm.com, gourry@gourry.net, hannes@cmpxchg.org, hughd@google.com, jack@suse.cz, jackmanb@google.com, jannh@google.com, jglisse@google.com, joshua.hahnjy@gmail.com, kas@kernel.org, lance.yang@linux.dev, liam@infradead.org, ljs@kernel.org, mathieu.desnoyers@efficios.com, matthew.brost@intel.com, mhiramat@kernel.org, mhocko@suse.com, peterx@redhat.com, pfalcato@suse.de, rakie.kim@sk.com, raquini@redhat.com, rdunlap@infradead.org, richard.weiyang@gmail.com, rientjes@google.com, rostedt@goodmis.org, rppt@kernel.org, ryan.roberts@arm.com, shivankg@amd.com, sunnanyong@huawei.com, surenb@google.com, thomas.hellstrom@linux.intel.com, tiwai@suse.de, usamaarif642@gmail.com, vbabka@suse.cz, vishal.moola@gmail.com, wangkefeng.wang@huawei.com, will@kernel.org, willy@infradead.org, yang@os.amperecomputing.com, ying.huang@linux.alibaba.com, ziy@nvidia.com, zokeefe@google.com, Usama Arif References: <20260605161422.213817-1-npache@redhat.com> <20260605161422.213817-13-npache@redhat.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: <20260605161422.213817-13-npache@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 5B7FD4000A X-Rspam-User: X-Stat-Signature: trbabdzurqubd1cmwa11qeh8xazmumo4 X-Rspamd-Server: rspam09 X-HE-Tag: 1780681791-754761 X-HE-Meta: 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 z2JtXzdt DVbKU/bma4XmiVfxrV892zLamOCqWq6cXr/5ikB3AY1MyV+lF0mYx8nmpTlp/DT/1C8D405VweatmKG/WEFrA5m/wpYkkSY8AWC2RYDWVI82aOo9o42AitXr88o1sjTKA+uyIbbO99haJIMumHgZEbIEPShkJF6SstPiZXZUfLfLgssIBgWUNt4PKIIIeuez3fhkZUFBHRo1GbJtNrdQAX/z7GWpUJrtuYqXz7gpL53upxQOmTA23a8n0JqJS+R7xCp0EcWvBROobFkA7qvOaKtdFdUelIO0i3JWZIchARlFjVvZoovHP1nX4MQmkJSdFndoyfBpDQZ7lwQmmhgNMN+Xq79uROADPHzE/jIIIAplkNN/uYFRaka2zDYPyPFsVZbvfd0sr/qkfn4c0IYE8JlqCMw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 6/5/26 18:14, Nico Pache wrote: > There are cases where, if an attempted collapse fails, all subsequent > orders are guaranteed to also fail. Avoid these collapse attempts by > bailing out early. > > Reviewed-by: Lorenzo Stoakes > Acked-by: Usama Arif > Acked-by: David Hildenbrand (Arm) > Signed-off-by: Nico Pache > --- > mm/khugepaged.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 430047316f43..7de92b28dd30 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -1499,6 +1499,7 @@ static enum scan_result mthp_collapse(struct mm_struct *mm, > collapse_address = address + offset * PAGE_SIZE; > ret = collapse_huge_page(mm, collapse_address, referenced, > unmapped, cc, order); > + Unrelated to this patch, but not the end of the world :) -- Cheers, David