From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 382BEC54E64 for ; Thu, 28 Mar 2024 12:25:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8BEDB6B0085; Thu, 28 Mar 2024 08:25:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 846876B0087; Thu, 28 Mar 2024 08:25:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 699176B0088; Thu, 28 Mar 2024 08:25:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 4753A6B0085 for ; Thu, 28 Mar 2024 08:25:12 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 0127C80CDD for ; Thu, 28 Mar 2024 12:25:11 +0000 (UTC) X-FDA: 81946367664.16.EC166D4 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf16.hostedemail.com (Postfix) with ESMTP id B04C918001C for ; Thu, 28 Mar 2024 12:25:09 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Spk1e1ih; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf16.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1711628709; 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=7+63Hd9S2maWm4+ZdrxvLvwS5wYvfXAyeqtS5+jlXWQ=; b=Cvyun20bDo502/vq46bRCBYd6hJzS4uiQFHI2MkDkfd0XjX+W5uiqm7bwGye2AWRCgmGO5 EVIQeyfP5Dy2lSSRNJdtJJluRXOrNKB4cIZJRsfdv9K8XkFh4SQRbGEAYI7lYQ0xI+Y0Og 79qk7PkPdHscQZ6XpZDMU7pctvC6Hj0= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=Spk1e1ih; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf16.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1711628709; a=rsa-sha256; cv=none; b=Qx9tm4VtQQIqTQ8qfv5C7C1zvOotl3wcWe3INBurBqH+81eS9vjlfxk9oyRi5jeQu9Zsic G5CUNdACRw7t82NV8qkTK/dqxeOg9OMN8Oawaj+NC8jFcNVWfCcT4IZpSrRCGrGGwy3ODj BhSYPidABrSMX3Ev7XC2LMh83syCvFU= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1711628709; h=from:from: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:autocrypt:autocrypt; bh=7+63Hd9S2maWm4+ZdrxvLvwS5wYvfXAyeqtS5+jlXWQ=; b=Spk1e1ihlU7qKeP0cOoVGMEXAk0MdwObDaEVOvx5qS49g5r8dbbjfYAZatk5iJepBPU5Iw jElEbU+IXXZhJvmCgKL+Q8Vz7CXe4DmxR2mh2z9kUqZy2oEY6dVSMHodmKrgbPBwhD3K6A PeSw+Zc+y1Ap0dO3etBs/fSFNHRymoM= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-519-PlMq-F0oPbC6brRDkAveHg-1; Thu, 28 Mar 2024 08:25:07 -0400 X-MC-Unique: PlMq-F0oPbC6brRDkAveHg-1 Received: by mail-wr1-f71.google.com with SMTP id ffacd0b85a97d-33ed22e92c2so521430f8f.0 for ; Thu, 28 Mar 2024 05:25:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711628706; x=1712233506; h=content-transfer-encoding:in-reply-to:organization:autocrypt :references:cc:to:from:content-language:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=7+63Hd9S2maWm4+ZdrxvLvwS5wYvfXAyeqtS5+jlXWQ=; b=FA0PGn1uf0ZPPW8v9JQvUH1CMkKbtOuq3HmsijTmltiMVEv9kM7LNUi5s5IMAjeSfQ doRlqgURCTA3Z8asm80ak6HfPTrvXUYgXmqBGpEVXWcvIbkwq/4QEIIN/vBI67aH9QTm kKcC0tdStRVfav+Pnngpzcn0Mq5DEZLW2GPAvMb0SNnK+lTPah76bHvM8LmbOxlTZFw7 AZN1pm2hpaSpEZKjVvU6auNwRkGlnU3MxewxrzbVjLvA5uw1rRb6MOvk8/21+7Sc8x9e +nyW/JUQOvdJ0hxfcDdOd3kZF45PLCPwc/PPnYlqcxHC3uJ3s5+UVA8mYeKvdoWa7dUv zYKw== X-Forwarded-Encrypted: i=1; AJvYcCWMi63TtWHyehM7R54wnD1WlwEqM5aT5wtAU5YqPDAFwz8tlBQR12NIAVV6bdwZJ/8aoGa3uYM1ZIW6GqJKgfqW+eg= X-Gm-Message-State: AOJu0YxBNI+V+DfN7gElEzhdD7cmMY2x9wbVu+lQ3SxXchKuH7NT0JoV B79M72r0OYs61LcWaiVpwmUFgyasqJviJeGlgIZ34dCyTkihhjOSfcOBjkmeb567jIsw7QfR3Hs Pn9MTSAc8A+Bn5gitRsAk/3gL58OxxBhO92aRqmXl++yVFsmo X-Received: by 2002:a5d:4903:0:b0:342:37da:30ad with SMTP id x3-20020a5d4903000000b0034237da30admr1916712wrq.35.1711628706285; Thu, 28 Mar 2024 05:25:06 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHay7YqNMkXCa1r37MY+OuMHSgQwyjSZm4Q9cdO+sLvwhUK4HgyAMBLTQyvR564mtp/kLZR1g== X-Received: by 2002:a5d:4903:0:b0:342:37da:30ad with SMTP id x3-20020a5d4903000000b0034237da30admr1916685wrq.35.1711628705793; Thu, 28 Mar 2024 05:25:05 -0700 (PDT) Received: from ?IPV6:2003:cb:c714:3600:8033:4189:6bd4:ea29? (p200300cbc7143600803341896bd4ea29.dip0.t-ipconnect.de. [2003:cb:c714:3600:8033:4189:6bd4:ea29]) by smtp.gmail.com with ESMTPSA id b10-20020a05600003ca00b00341c563aacbsm1671771wrg.1.2024.03.28.05.25.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 28 Mar 2024 05:25:05 -0700 (PDT) Message-ID: <3f465638-f96f-4d81-87b2-779897c03b21@redhat.com> Date: Thu, 28 Mar 2024 13:25:04 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] mm: support multi-size THP numa balancing From: David Hildenbrand 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: <0baa443a-7872-4ded-94c6-06af88a6a943@linux.alibaba.com> <760800b1-c708-4c1d-b153-c252ab21938a@redhat.com> 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: <760800b1-c708-4c1d-b153-c252ab21938a@redhat.com> 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: 8bit X-Rspamd-Queue-Id: B04C918001C X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: u9itdddi5zb64pwycz6t4yrbqwsxupr7 X-HE-Tag: 1711628709-191118 X-HE-Meta: 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 L28oY51v 9qEvBmBMoKCnuC+vJlSNnvBRIMmit3st+sM64aOsRnc0EUXs6fZRN9avRbAHivmdkoVg32m28pf25iATm44WsTSx+hpWW4WZVrdw4Q7qTvg3hYWgJBaKtlGaC+kJvrNhg7zEmnF9gdEyek99/LZ92pzVCmno9WSbx/I9Civw3nRhrjqDYT6ej9NQBCNlCRd9MylU151iMStqhG11u4FIkD1ltkupdwwTWqFCkeoojdr8VZU87mIGeW8Mem6/v0pxIAMM0aawDv9EBxope86mtlAUP8TxRxf6LUvtXKitnvRfSVA+WWWgsjxdL06wgVB9FZHfsRHF/QUzF7EcYWTRsya8mR6T0IX1Wr0D4VaecnoWTVDvyx+Miurwph8dYlM3EtHlyceqK59nXcIx6XDsQRAT1+HJ424vg9FHHkEpRBNoOFjovaPej8Xq00vN90n9qo+dqLHgfhRW1M+uvsEpkE5EBDavs5hfbeevHiSWv8YFMWVIROZ5MHu45yILrMRxOD85VXYSzaPNEanpxLv7ujc2s3pMQtZxhfdBsMbDSwOTwTqPSJPN03jgbynLgWxVGSGrIYYZ9qCHE383CvcIA5iF5pg== 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 28.03.24 13:07, David Hildenbrand wrote: > On 28.03.24 12:34, Baolin Wang wrote: >> >> >> On 2024/3/28 17:25, David Hildenbrand wrote: >>> 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) >> >> Seems folio_pte_batch() is not suitable for numa balancing, since we did >> not care about other PTE bits, only care about the protnone bits. And > > You should be able to ignore most bits we care about, which case are you > concerned about folio_pte_batch() would miss. Hand crafting own > functions to cover some corner cases nobody cares about is likely a bad > idea. Note that the reason why I am asking is that folio_pte_batch() can optimize-out repeated ptep_get() with cont-ptes. -- Cheers, David / dhildenb