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[2003:cb:c714:3600:8033:4189:6bd4:ea29]) by smtp.gmail.com with ESMTPSA id u12-20020a05600c19cc00b00414659ba8c2sm1685458wmq.37.2024.03.28.02.25.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 28 Mar 2024 02:25:06 -0700 (PDT) Message-ID: Date: Thu, 28 Mar 2024 10:25:05 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] mm: support multi-size THP numa balancing To: Baolin Wang , akpm@linux-foundation.org Cc: mgorman@techsingularity.net, wangkefeng.wang@huawei.com, jhubbard@nvidia.com, ying.huang@intel.com, 21cnbao@gmail.com, ryan.roberts@arm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: 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: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 6A010100020 X-Stat-Signature: 9diwjaduan6o118tjgdz8w3k1nr65joc X-Rspam-User: X-HE-Tag: 1711617911-95500 X-HE-Meta: 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 7nw+6eEg 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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 26.03.24 12:51, Baolin Wang wrote: > Now the anonymous page allocation already supports multi-size THP (mTHP), > but the numa balancing still prohibits mTHP migration even though it is an > exclusive mapping, which is unreasonable. > > Allow scanning mTHP: > Commit 859d4adc3415 ("mm: numa: do not trap faults on shared data section > pages") skips shared CoW pages' NUMA page migration to avoid shared data > segment migration. In addition, commit 80d47f5de5e3 ("mm: don't try to > NUMA-migrate COW pages that have other uses") change to use page_count() > to avoid GUP pages migration, that will also skip the mTHP numa scaning. > Theoretically, we can use folio_maybe_dma_pinned() to detect the GUP > issue, although there is still a GUP race, the issue seems to have been > resolved by commit 80d47f5de5e3. Meanwhile, use the folio_likely_mapped_shared() > to skip shared CoW pages though this is not a precise sharers count. To > check if the folio is shared, ideally we want to make sure every page is > mapped to the same process, but doing that seems expensive and using > the estimated mapcount seems can work when running autonuma benchmark. > > Allow migrating mTHP: > As mentioned in the previous thread[1], large folios (including THP) are > more susceptible to false sharing issues among threads than 4K base page, > leading to pages ping-pong back and forth during numa balancing, which is > currently not easy to resolve. Therefore, as a start to support mTHP numa > balancing, we can follow the PMD mapped THP's strategy, that means we can > reuse the 2-stage filter in should_numa_migrate_memory() to check if the > mTHP is being heavily contended among threads (through checking the CPU id > and pid of the last access) to avoid false sharing at some degree. Thus, > we can restore all PTE maps upon the first hint page fault of a large folio > to follow the PMD mapped THP's strategy. In the future, we can continue to > optimize the NUMA balancing algorithm to avoid the false sharing issue with > large folios as much as possible. > > Performance data: > Machine environment: 2 nodes, 128 cores Intel(R) Xeon(R) Platinum > Base: 2024-03-25 mm-unstable branch > Enable mTHP to run autonuma-benchmark > > mTHP:16K > Base Patched > numa01 numa01 > 224.70 137.23 > numa01_THREAD_ALLOC numa01_THREAD_ALLOC > 118.05 50.57 > numa02 numa02 > 13.45 9.30 > numa02_SMT numa02_SMT > 14.80 7.43 > > mTHP:64K > Base Patched > numa01 numa01 > 216.15 135.20 > numa01_THREAD_ALLOC numa01_THREAD_ALLOC > 115.35 46.93 > numa02 numa02 > 13.24 9.24 > numa02_SMT numa02_SMT > 14.67 7.31 > > mTHP:128K > Base Patched > numa01 numa01 > 205.13 140.41 > numa01_THREAD_ALLOC numa01_THREAD_ALLOC > 112.93 44.78 > numa02 numa02 > 13.16 9.19 > numa02_SMT numa02_SMT > 14.81 7.39 > > [1] https://lore.kernel.org/all/20231117100745.fnpijbk4xgmals3k@techsingularity.net/ > Signed-off-by: Baolin Wang > --- > mm/memory.c | 56 +++++++++++++++++++++++++++++++++++++++++++-------- > mm/mprotect.c | 3 ++- > 2 files changed, 50 insertions(+), 9 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index c30fb4b95e15..36191a9c799c 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -5068,16 +5068,55 @@ static void numa_rebuild_single_mapping(struct vm_fault *vmf, struct vm_area_str > update_mmu_cache_range(vmf, vma, vmf->address, vmf->pte, 1); > } > > +static void numa_rebuild_large_mapping(struct vm_fault *vmf, struct vm_area_struct *vma, > + struct folio *folio, pte_t fault_pte, bool ignore_writable) > +{ > + int nr = pte_pfn(fault_pte) - folio_pfn(folio); > + unsigned long start = max(vmf->address - nr * PAGE_SIZE, vma->vm_start); > + unsigned long end = min(start + folio_nr_pages(folio) * PAGE_SIZE, vma->vm_end); > + pte_t *start_ptep = vmf->pte - (vmf->address - start) / PAGE_SIZE; > + bool pte_write_upgrade = vma_wants_manual_pte_write_upgrade(vma); > + unsigned long addr; > + > + /* Restore all PTEs' mapping of the large folio */ > + for (addr = start; addr != end; start_ptep++, addr += PAGE_SIZE) { > + pte_t pte, old_pte; > + pte_t ptent = ptep_get(start_ptep); > + bool writable = false; > + > + if (!pte_present(ptent) || !pte_protnone(ptent)) > + continue; > + > + if (vm_normal_folio(vma, addr, ptent) != folio) > + continue; > + Should you be using folio_pte_batch() in the caller to collect all applicable PTEs and then only have function that batch-changes a given nr of PTEs? (just like we are now batching other stuff) -- Cheers, David / dhildenb