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 88224C8303D for ; Fri, 4 Jul 2025 10:34:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1F9216B803B; Fri, 4 Jul 2025 06:34:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1A95D6B8035; Fri, 4 Jul 2025 06:34:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 071AC6B803B; Fri, 4 Jul 2025 06:34:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id E88286B8035 for ; Fri, 4 Jul 2025 06:34:55 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 9A0B71A032B for ; Fri, 4 Jul 2025 10:34:55 +0000 (UTC) X-FDA: 83626224150.10.B1E7F11 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf14.hostedemail.com (Postfix) with ESMTP id 1832E10000B for ; Fri, 4 Jul 2025 10:34:52 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=XcskIKar; spf=pass (imf14.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1751625293; 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=kKC81+LYTS9wDqjhPfqay6re/S41xaelqqyXV7r8kmQ=; b=jDpoW5NqosrgDiARnCkbhL2Jg0KFANjY3QYYuxgBYjnBs3lpxMbcAQck9IhG9EH4HbIKxm f/fhgLLV/sMCk0CQ2CleQckdYbWc8oHurEMgh40gmWTVt3RhcqyQaEixlhX+V0UcMLcK4B XVHrE8X2M5OpIBeXEiuzX5uYubiMF4s= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=XcskIKar; spf=pass (imf14.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1751625293; a=rsa-sha256; cv=none; b=MpXlabqrueEE8kqPWUY7XcqkwVcdaJygvvpnBS3Qo85E22K6/oLpJE6P4vbna4X8OmB3W1 58BbvNJXTIXg4VQLWIlfjfW7CCHOLtBaSY8U7nk29+1JrpxrxsHWhoX0d/LXR+Lk/KgR0M mRGSI7qxlG4dVFLMN0DeIFH3Q/5XDJk= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1751625292; 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=kKC81+LYTS9wDqjhPfqay6re/S41xaelqqyXV7r8kmQ=; b=XcskIKar8bIffTs7mkYRUQ2Rniw9UrkhO4AbQhugOfsYheFhpq7D8F5QqkjHrtiRYFPIFn yETygTx8WOP/m/HPFuq4eXpXg7lzThayIvq4qyHuIio0BYwJbe/8tE+qk66x9eO+arMA6r Ev73Qm5VmhBwOT3r5JKoK6ciLZm3Vg8= 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-610-oI1Rdr1jOqme-ZIqc7GcYA-1; Fri, 04 Jul 2025 06:34:51 -0400 X-MC-Unique: oI1Rdr1jOqme-ZIqc7GcYA-1 X-Mimecast-MFC-AGG-ID: oI1Rdr1jOqme-ZIqc7GcYA_1751625290 Received: by mail-wr1-f71.google.com with SMTP id ffacd0b85a97d-3a4f858bc5eso543972f8f.0 for ; Fri, 04 Jul 2025 03:34:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1751625290; x=1752230090; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=kKC81+LYTS9wDqjhPfqay6re/S41xaelqqyXV7r8kmQ=; b=OuFRj+p9aiFG4EqKp5DnL5JsmHHGHUrYc7ns9bfzNPH18xVEFSuU5gZ2SqkXtqyJh4 4GzthnFSYVACfU1V/puEsJUj3hRbjHiIoj7IDiYRPwvstYgO5J1UVZh0zVSRQ0VAWRvk XPwwabX90a7lh94uaGHap+GZdNcjHIY75YvCIlUX3siz1gvtw0Utc8FBqGUp6ekW4hL5 M/JGyPIMQ527MgI7eXEYdROSFv6Bdsk2mkCAYasCMv4+uMPgVW0WLrFiX18kdLbN+H7q QDvaSd9aHIB6OPPkLQThMhBzjB2cE1RHTOwxgJ43Ur/L37eNX+0Veh/h9VIqmxWpXU4o Rv2Q== X-Gm-Message-State: AOJu0Yy+VK5VIf/hB0x+wRcFCsHKSnWvYq+Fq4M0WQYGRBkb4tE67gER YtYdGxGidQwjDgWlqjACe+9Mn+SdBiRUw4gckpLgN8NFeGkVaIVx0d6AfOanLmnGrwpkgMenc5N WUCSwGn8GYjyXJahg4rOHIj+l3rai1sIgfHW9tew28catQIynLMrN X-Gm-Gg: ASbGncsZkG3jEu9e84RVMsT4HzBRno4fpj41S8xA7a2qS2TH4X1fNGTP9rPKKiSGY1H CZFncWfRgumPzIOdeOZYyQKBv6FBQmrhpD3zkwvbhnOH5h9hd7cbr3l+K6y3Sem6o3m/yiR6ic0 Un+1Gz20QmfXHG53mkHiiWI0LyS7Cy62uv7NM6En5K6RA3J90XEh4NPjpk9cI4390CSKaJy+IEk bICQt/1oEQq/EzSOKYLeA1EBHWfe1Ymbl1dY3U7ZM5t08tH9LZSHCoVs5CX/I65lW0tFDrDmlze jXlsaVsgiKjKuCFiFQ9CJMtemYWuZZRdgycPXKYxnnILWYoGX8lgDkyCNvp+uNmfF5TfNjpAXW0 m1moqps0Vq6CIJHu9JTlYFBgcARw8eKN/L6AynqIl1cOJOHw= X-Received: by 2002:a05:6000:1448:b0:3a4:f7df:baf5 with SMTP id ffacd0b85a97d-3b496fadcbamr1366205f8f.0.1751625290012; Fri, 04 Jul 2025 03:34:50 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEqf1Mi5wCwlJzafl3k2+mdXvo4trSBHCVtKMwjAlL2Yv75Jprtj4nGpW3i3ft7VcKsW2kJeg== X-Received: by 2002:a05:6000:1448:b0:3a4:f7df:baf5 with SMTP id ffacd0b85a97d-3b496fadcbamr1366165f8f.0.1751625289554; Fri, 04 Jul 2025 03:34:49 -0700 (PDT) Received: from ?IPV6:2003:d8:2f2c:5500:988:23f9:faa0:7232? (p200300d82f2c5500098823f9faa07232.dip0.t-ipconnect.de. [2003:d8:2f2c:5500:988:23f9:faa0:7232]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3b470caa1b3sm2115225f8f.43.2025.07.04.03.34.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 04 Jul 2025 03:34:49 -0700 (PDT) Message-ID: <38aea444-a404-4176-8702-496362c88cfa@redhat.com> Date: Fri, 4 Jul 2025 12:34:47 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [DISCUSSION] proposed mctl() API To: SeongJae Park , Usama Arif Cc: linux-mm@kvack.org, Andrew Morton , Shakeel Butt , "Liam R . Howlett" , Vlastimil Babka , Jann Horn , Arnd Bergmann , Christian Brauner , Mike Rapoport , Johannes Weiner , Barry Song <21cnbao@gmail.com>, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Pedro Falcato , Matthew Wilcox , Lorenzo Stoakes References: <20250702173816.59935-1-sj@kernel.org> 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: <20250702173816.59935-1-sj@kernel.org> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: VuFUrXloL3oxMiiI0NNBseBZ2BZBZJRveNrvs2zPin4_1751625290 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: x7zgzxeqekbpmzqm9gdotfi71ou7tcxk X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 1832E10000B X-HE-Tag: 1751625292-573346 X-HE-Meta: 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 GYGE/F/I DStsSKDLd7kk2fvz/PT5UYbRe7VY8us3lUynCHgTj6WhtytX0eDvBp5NBu3bueTO1GeQaQmsdDHesuO20LK+dOjFmwCEE65Q6gX9POt/TjMMwUP6xwmt78AegRsFP/OWfXlu3lS7agGuGTAG8TZO2iVbVFw0D/qfSSm1bBa6UcUQNilQ5HDx1/g+vx3DlfaW8lfCsbml3N/0C1BHDjXIFinqApFtIFVaAcem6aX9neTm8QJasWEGvFlCEVXQZoye2dGxCfCGMCDkX1ecz4hY62IoXd/srOJ7Ocip3X5nICGjmzZomyfATdiJ/XxIT7o8fbDOdiCOh0XVMvmf3SkaS6laz13sz8uJRceNwl/X0GStN42rpNzYydJpQf5yWCHg756dZJy1BzfX0X8MYj/mziNJvEBEFkGWugA+eEa1fsK1BLTsPy+KUckuXtpGjCpLq5/vMawzk0/zHEQwVygLgH0Jd1yZNwIQGUfzplsELIPN4OSg= 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 02.07.25 19:38, SeongJae Park wrote: > On Wed, 2 Jul 2025 15:15:01 +0100 Usama Arif wrote: > > [...] >> In terms of the approach of doing this, IMHO, I dont think the way to do this >> is controversial. After the great feedback from Lorenzo on the prctl series, the >> approach would be for userpsace to make a call that just does for_each_vma of the process, >> madvises the VMAs, > > One dirty hack that I can think off the top of my head for doing this without > new kernel changes is, unsurprisingly, using DAMOS. Using DAMOS, users can do > madvise(MADV_HUGEPAGE) to virtual address ranges of specific access patterns. > It is aimed to be used for hot regions, while using similar one of > MADV_NOHUGEPAGE for cold regions. An experiment with a prototype[1] showed it > eliminates about 80% of internal fragmentation caused memory overhead while > keeping 46% of performance improvement under a constrained situation. > > If you set the access pattern as any pattern, hence, you can do > madvise(MADV_HUGEPAGE) for effectively entire virtual address space of the > process. DAMON user-space tool supports periodically tracking childs and > applying same DAMOS scheme to those. So, for example, below hack could be > tried. > > # damo start $(pidof XXX) --damos_action hugepage --include_child_tasks IIRC, setting MADV_HUGEPAGE on arbitrary VMAs from arbitrary processes has the potential of breaking applications. Just imagine them deliberately setting MADV_NOHUGEPAGE and are intending of using userfaultfd, where it is crucial that we don't over-allocate memory even before userfaultdf is actually registered. (QEMU does that) -- Cheers, David / dhildenb