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 49B3FC30658 for ; Fri, 5 Jul 2024 08:59:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A98106B009E; Fri, 5 Jul 2024 04:59:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A21746B009F; Fri, 5 Jul 2024 04:59:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 84C9E6B00A0; Fri, 5 Jul 2024 04:59:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 60D306B009E for ; Fri, 5 Jul 2024 04:59:10 -0400 (EDT) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 289518181B for ; Fri, 5 Jul 2024 08:59:10 +0000 (UTC) X-FDA: 82305099660.09.827A9AF Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf13.hostedemail.com (Postfix) with ESMTP id E487820024 for ; Fri, 5 Jul 2024 08:59:07 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=PjC9UMzd; spf=pass (imf13.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1720169934; 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=ynx6wgANHF6xng2dJQISpo0Kqzb6hlq28TB2397xxYw=; b=0kX+sqUhK5lOAlHoVfMzX/F4Nnez6NeL+VMRdnlnkr7rcLqFqcGl+iiuCwekhvGFP5MsVr d15DY+ypyS5MwFf36st5iwrVj0CbE119Vb7H8xywDY5FwEz2+Vch5Hr2ZuzUY3FCp9Cnh0 6z7xIrv4hgc/2MFHR9kF/JMr288xK+8= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=PjC9UMzd; spf=pass (imf13.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1720169934; a=rsa-sha256; cv=none; b=e4r3EavugW+abbKnsRKdAmTR1pFWEV4Xuhv7bMabIFjdP6bPAp39o1mSI7ytnB+Gjx5Dxx YnJvXiBWejC81RoeFZRlmb06L0UvN41b25TdYcxdbzUPLmtEACN5b/xRe7QvfS7iFiy86d mtJNC/GjhUpFHieOXXGSi/lIw2XWNlw= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1720169947; 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=ynx6wgANHF6xng2dJQISpo0Kqzb6hlq28TB2397xxYw=; b=PjC9UMzd4CIKDEtXW8DU6q9H2jMV85QGOWty1esJC4nuRlBshSJc81RwdtA1OqvIP8Uf4q V7sgjv8uCF88yX0IGQMIh0SnyWPmWQHOWa0iQgGRTBLqMM22R0h7o7NDLtkoIEifumrG8J 97gkpU+ru3M7N2HYs/GdQAiudPMpTno= Received: from mail-lf1-f71.google.com (mail-lf1-f71.google.com [209.85.167.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-134-_mlxhBKjNRuHFjjyQejVag-1; Fri, 05 Jul 2024 04:59:05 -0400 X-MC-Unique: _mlxhBKjNRuHFjjyQejVag-1 Received: by mail-lf1-f71.google.com with SMTP id 2adb3069b0e04-52e993e31a9so1372554e87.1 for ; Fri, 05 Jul 2024 01:59:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720169944; x=1720774744; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :content-language: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=ynx6wgANHF6xng2dJQISpo0Kqzb6hlq28TB2397xxYw=; b=sOW4WEahKHzhUtVvzkagTUJad86ZwSWrHeQxQxywmBNcikI5gRiVFH9ynNCYee5yXQ Di8NDLinmJLfnIJNTBAqZ7BlxOMGen2+dl+PZfE3yF3/1RMc/2/W/BXo7JzZZCgddaC7 Z0+1cn3rLsP8/o+0cOSxw0QOftsMlFYIIirP3JJVhJxiHI1lHOiD+dXdZnwkHUtAund8 eTiOWsmXoSXJUZwSxQ3aVmmeXGoTKp+LvX8Bp9vw1lXvGe/uVL41B6G0Xn8QE+SAKinS wFhcn2PwDCReAz5Z5YxLZdUKQwD9tZ4R+6XIphuIQBfmv+vSFILcQ+qjP7gYgeLC7FVi An6g== X-Forwarded-Encrypted: i=1; AJvYcCV2A2qYvOHDVxBBBIWzmi17uixYEIns+gYxLIMNDr9GTDxrr87Tb5P4ujTOv92X4qFAAAgGGak8l2NjPP+TweSrinc= X-Gm-Message-State: AOJu0Yy4pT6PZcbbgpwZDr8Nv3AaNpM1BVwPUaLOtEX3JMBc0Wsj9iva rRdd0hrIXv0v2e3bIEaQNIwAY+jn8RiS4vRBeipkaJH22HNSe8hKzmiUZnysdTZjNol3BM1hfDi MUVhEOkRMVQjf4RXpRN+IF/TRYBGiJ9pt6zwM4XLn4ENu5ITe X-Received: by 2002:ac2:5227:0:b0:52c:9d31:3f25 with SMTP id 2adb3069b0e04-52ea06c8ba0mr2596361e87.43.1720169944147; Fri, 05 Jul 2024 01:59:04 -0700 (PDT) X-Google-Smtp-Source: AGHT+IF4wtNKCyJUxyKgRpeaDjhaf3qr+qwyUGYEqLpPHVMlL/r7z32HWRl15S5kMSb3IdJWPGOQ0Q== X-Received: by 2002:ac2:5227:0:b0:52c:9d31:3f25 with SMTP id 2adb3069b0e04-52ea06c8ba0mr2596340e87.43.1720169943726; Fri, 05 Jul 2024 01:59:03 -0700 (PDT) Received: from ?IPV6:2003:cb:c702:b500:3ed7:a1c7:447e:2279? (p200300cbc702b5003ed7a1c7447e2279.dip0.t-ipconnect.de. [2003:cb:c702:b500:3ed7:a1c7:447e:2279]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-42651531f1fsm17678905e9.0.2024.07.05.01.59.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 05 Jul 2024 01:59:03 -0700 (PDT) Message-ID: <32f04739-0cd0-4a9e-9419-c5a13c333c28@redhat.com> Date: Fri, 5 Jul 2024 10:59:02 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 0/6] add mTHP support for anonymous shmem To: Ryan Roberts , Baolin Wang , Matthew Wilcox Cc: akpm@linux-foundation.org, hughd@google.com, wangkefeng.wang@huawei.com, ying.huang@intel.com, 21cnbao@gmail.com, shy828301@gmail.com, ziy@nvidia.com, ioworker0@gmail.com, da.gomez@samsung.com, p.raghav@samsung.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <27beaa0e-697e-4e30-9ac6-5de22228aec1@redhat.com> <6d4c0191-18a9-4c8f-8814-d4775557383e@redhat.com> 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: 8bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: E487820024 X-Stat-Signature: p13oaympbem9jazi8h1618rsuz886mrf X-Rspam-User: X-HE-Tag: 1720169947-128761 X-HE-Meta: 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 NdIh+4ry NBZWGNyhfMbChZ+xRwMy9Sge9xE8LIS4FjgA5LGTETTuV9Fv63nhyL4aXBf1uYA04gucn7A9NkRBfFcaMmUtsJ6RXFKGX19HCGvKTYLOxG0nBHn7sXil8SAXXlrt6yLlLBpHcIHCsju4n0oWD4YLdpclFUr/FyFQUKQ0wG0a8kTG2q4sWFiXNPT+Jr4jNORNBpw2w4WQ3sZZ7ikFn6jouY/yPNot1dFcLdQPiU3k++pKTSNjFj/w5sPD6eJtZkKVZNq3zYYC5jRbEUaw985o9krwFrn1gWooNh2u6J2cxwPfbkOlQCYr7O9/LSI/Q2/4v20vs/8phEEBPSQTcemXrDFUjmfuRAWJr3DnPmo+TbeKq6VBOwPfG4vkNnd6dURlEFRw2XNtGSu1Ev1orG1lhR4cwtut1lsT1Dij/wtcH2GQAUs5EKV6NpVjG04g6r89WBrNTuK9TegUwV98vw7deEg9/xznu4FFeEUNt 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 05.07.24 10:45, Ryan Roberts wrote: > On 05/07/2024 06:47, Baolin Wang wrote: >> >> >> On 2024/7/5 03:49, Matthew Wilcox wrote: >>> On Thu, Jul 04, 2024 at 09:19:10PM +0200, David Hildenbrand wrote: >>>> On 04.07.24 21:03, David Hildenbrand wrote: >>>>>> shmem has two uses: >>>>>> >>>>>>     - MAP_ANONYMOUS | MAP_SHARED (this patch set) >>>>>>     - tmpfs >>>>>> >>>>>> For the second use case we don't want controls *at all*, we want the >>>>>> same heiristics used for all other filesystems to apply to tmpfs. >>>>> >>>>> As discussed in the MM meeting, Hugh had a different opinion on that. >>>> >>>> FWIW, I just recalled that I wrote a quick summary: >>>> >>>> https://lkml.kernel.org/r/f1783ff0-65bd-4b2b-8952-52b6822a0835@redhat.com >>>> >>>> I believe the meetings are recorded as well, but never looked at recordings. >>> >>> That's not what I understood Hugh to mean.  To me, it seemed that Hugh >>> was expressing an opinion on using shmem as shmem, not as using it as >>> tmpfs. >>> >>> If I misunderstood Hugh, well, I still disagree.  We should not have >>> separate controls for this.  tmpfs is just not that special. > > I wasn't at the meeting that's being referred to, but I thought we previously > agreed that tmpfs *is* special because in some configurations its not backed by > swap so is locked in ram? There are multiple things to that, like: * Machines only having limited/no swap configured * tmpfs can be configured to never go to swap * memfd/tmpfs files getting used purely for mmap(): there is no real difference to MAP_ANON|MAP_SHARE besides the processes we share that memory with. Especially when it comes to memory waste concerns and access behavior in some cases, tmpfs behaved much more like anonymous memory. But there are for sure other use cases where tmpfs is not that special. My opinion is that we need to let people configure orders (if you feel like it, configure all), but *select* the order to allocate based on readahead information -- in contrast to anonymous memory where we start at the highest order and don't have readahead information available. Maybe we need different "order allcoation" logic for read/write vs. fault, not sure. But I don't maintain that code, so I can only give stupid suggestions and repeat what I understood from the meeting with Hugh and Kirill :) -- Cheers, David / dhildenb