From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C5ADB5BAF0 for ; Thu, 7 Aug 2025 05:55:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754546135; cv=none; b=Kh7q2yqiJ1AYmrtnHpnZ48vVp+s2Zcil6UIOIjeWznR+mxWGvINGZn4MJLqyHXH6T+yRR2heAeID1lBml6Du5eHoEFmakIOUUEqlYs7V9kTvZxhzL6y1BHk1W2Ako2Zc0Aaanas5tpNzRZwGeWmTBqJfXlJtm+PLwO+4YVPwN2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754546135; c=relaxed/simple; bh=q91oghgucfy4d/4IJR8jb5aBP3fpyShUx8waoI1W7mo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=OUPfxn8btzGLSC5fKAgcwMOWBWw0Ro+7i6I4VLJ570x5bQyEMJqR1hWsaHRIOhvnwvU1Rbrm91uqMUuU40XRtMlbjSAmQOyJBLqofAsmRLqexe6Yx2pIAopoL3l/aRC7F1jScdSwIbDFBF8r8cvFcbLKU71BFovcJbAa1wB8GHs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=U6Oeos/4; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="U6Oeos/4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1754546132; 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=p7T7nHeTlN9HwipzMNJDP8Bfwjs2xG35T+M5i7PC0Cw=; b=U6Oeos/4aSMPttyd/8AiqJIH2PymVqeq4g6SdzsZIiBPs/voe0+/C6r4CuxfzgeNcpsk2M o2w66/pow6ETWMxSO25C72OwSJI9XUX4CIFK/iI4QFfbUWlFWByXpd/HYfXQNDHKJaLolY b0osuL2FoUaoKkj9cAipV2AWRbLCPZ4= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-215-c1__is09NyecKEWetct35Q-1; Thu, 07 Aug 2025 01:55:31 -0400 X-MC-Unique: c1__is09NyecKEWetct35Q-1 X-Mimecast-MFC-AGG-ID: c1__is09NyecKEWetct35Q_1754546130 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-3b783265641so237206f8f.1 for ; Wed, 06 Aug 2025 22:55:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1754546130; x=1755150930; 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=p7T7nHeTlN9HwipzMNJDP8Bfwjs2xG35T+M5i7PC0Cw=; b=w3Ns/Ocb88FfGeOjvbIVIcnIOxoGTrKTE4L41/5MQwiyZ3rEkJWB83EjUF4/FWoLNT vfRIzzgx9wXf7DNhkS6YRWxHPXakvEMlZUauySqTXW0UERiMTZY4Cs0Kem4J8IkVr02t +fAQsgc2fO+5WoVzTDpM3zIh9WXnm19G+QQPUlc4y0onRZpk7JP/p49JPjgUA45hUeRT A0WZFtaRLGeXs3PTyoDlNw0Akfa0OAQ9qC4KzYbXYbfeRRoP9ZXiyUpVuRfLcryHfVfi vz493RX8F29GMG8OCo3pDs/ThOSPnB3+X4eoUXkBMbYm4XDk5+rqBFw/WYW65/lvIRJs YCwQ== X-Forwarded-Encrypted: i=1; AJvYcCVw7sDuPObuJsJXnXjwcCeRhuquBX1KpOJV6T38dRgmDv2RC/Yugr8mfbgMK4d+xWML2g2Bu9uoEejYm2k=@vger.kernel.org X-Gm-Message-State: AOJu0YwFEF/K1WHHhMz7VLyWhkJVsrgRBV4+HqN7qnQQdTT/RNkCROxk 4MBOZnfzhcTYpZTNRSJH6xl7jhGgnj9lroAZ39CCL8gLzD8co1CQ0gvFB/pPIR3B8SVDDhVymBH uE2INy1sn9pOs0sGmE8kKKWCzDCSBv//pb+Uyt9awIex2AfR/9/WNxI1VJbG+sY2lVg== X-Gm-Gg: ASbGncvc+1l11zPNfsEWOBpsC6i1Dd/xiS9zGQm3lxTE2NYJjPYkyeuzzDAVZr9oReW CMcQdc5cJMjnIuP2KFKrH9N9o2FZTjz2ZbcrhvpnzVAsaR4RiZlGI78nrX2e8/URS+eAVGBmqLT 53Or04oDGSikVSJYndtLV71J8GwvaG+Jg3sVZyqg2wNmJlfhLp0kmvJ9gAXL9NXGtX1wqT718TZ StvxGqKAixMDqfdY2MUMCCf9rGwNmF6SzMn1vmXwj4qG2tNbWfHUHQPZggYzAuoxTtSTBxop1sy flvCAq/IsqASiWpeyQ2qDk9fBETXDhvizdNVrpW6T3H0mySXZYvJHnh3vSzYBGbJnkhjTg== X-Received: by 2002:a05:6000:4308:b0:3b7:99a8:bf6e with SMTP id ffacd0b85a97d-3b8f41d50afmr4804893f8f.51.1754546129991; Wed, 06 Aug 2025 22:55:29 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHrCIxSNpL5yXQYQfvCpzINdTrOpqDRRm3qfN0xJSXs+Wik+zOu53yB4YxDQ7mNhDwLqABUIg== X-Received: by 2002:a05:6000:4308:b0:3b7:99a8:bf6e with SMTP id ffacd0b85a97d-3b8f41d50afmr4804861f8f.51.1754546129574; Wed, 06 Aug 2025 22:55:29 -0700 (PDT) Received: from [192.168.3.141] (p57a1aa57.dip0.t-ipconnect.de. [87.161.170.87]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3b79c3ac115sm25527853f8f.12.2025.08.06.22.55.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 06 Aug 2025 22:55:28 -0700 (PDT) Message-ID: <2fa2f288-bb82-4a9b-8dec-3a4c768fb970@redhat.com> Date: Thu, 7 Aug 2025 07:55:27 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH v2] mm/zswap: store Cc: Nhat Pham , SeongJae Park , "Liam R. Howlett" , Andrew Morton , Chengming Zhou , Johannes Weiner , Jonathan Corbet , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , Yosry Ahmed , kernel-team@meta.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Takero Funaki References: <20250805002954.1496-1-sj@kernel.org> <761a2899-6fd9-4bfe-aeaf-23bce0baa0f1@redhat.com> <055a8a69-731d-43b8-887e-54d8718877cb@redhat.com> From: David Hildenbrand Content-Language: en-US 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/g1oFAmgsLPQFCRvGjuMACgkQTd4Q 9wD/g1o0bxAAqYC7gTyGj5rZwvy1VesF6YoQncH0yI79lvXUYOX+Nngko4v4dTlOQvrd/vhb 02e9FtpA1CxgwdgIPFKIuXvdSyXAp0xXuIuRPQYbgNriQFkaBlHe9mSf8O09J3SCVa/5ezKM OLW/OONSV/Fr2VI1wxAYj3/Rb+U6rpzqIQ3Uh/5Rjmla6pTl7Z9/o1zKlVOX1SxVGSrlXhqt kwdbjdj/csSzoAbUF/duDuhyEl11/xStm/lBMzVuf3ZhV5SSgLAflLBo4l6mR5RolpPv5wad GpYS/hm7HsmEA0PBAPNb5DvZQ7vNaX23FlgylSXyv72UVsObHsu6pT4sfoxvJ5nJxvzGi69U s1uryvlAfS6E+D5ULrV35taTwSpcBAh0/RqRbV0mTc57vvAoXofBDcs3Z30IReFS34QSpjvl Hxbe7itHGuuhEVM1qmq2U72ezOQ7MzADbwCtn+yGeISQqeFn9QMAZVAkXsc9Wp0SW/WQKb76 FkSRalBZcc2vXM0VqhFVzTb6iNqYXqVKyuPKwhBunhTt6XnIfhpRgqveCPNIasSX05VQR6/a OBHZX3seTikp7A1z9iZIsdtJxB88dGkpeMj6qJ5RLzUsPUVPodEcz1B5aTEbYK6428H8MeLq NFPwmknOlDzQNC6RND8Ez7YEhzqvw7263MojcmmPcLelYbfOwU0EVcufkQEQAOfX3n0g0fZz 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+DWgUCaCwtJQUJG8aPFAAKCRBN3hD3AP+DWlDnD/4k2TW+HyOOOePVm23F5HOhNNd7nNv3 Vq2cLcW1DteHUdxMO0X+zqrKDHI5hgnE/E2QH9jyV8mB8l/ndElobciaJcbl1cM43vVzPIWn 01vW62oxUNtEvzLLxGLPTrnMxWdZgxr7ACCWKUnMGE2E8eca0cT2pnIJoQRz242xqe/nYxBB /BAK+dsxHIfcQzl88G83oaO7vb7s/cWMYRKOg+WIgp0MJ8DO2IU5JmUtyJB+V3YzzM4cMic3 bNn8nHjTWw/9+QQ5vg3TXHZ5XMu9mtfw2La3bHJ6AybL0DvEkdGxk6YHqJVEukciLMWDWqQQ RtbBhqcprgUxipNvdn9KwNpGciM+hNtM9kf9gt0fjv79l/FiSw6KbCPX9b636GzgNy0Ev2UV m00EtcpRXXMlEpbP4V947ufWVK2Mz7RFUfU4+ETDd1scMQDHzrXItryHLZWhopPI4Z+ps0rB CQHfSpl+wG4XbJJu1D8/Ww3FsO42TMFrNr2/cmqwuUZ0a0uxrpkNYrsGjkEu7a+9MheyTzcm vyU2knz5/stkTN2LKz5REqOe24oRnypjpAfaoxRYXs+F8wml519InWlwCra49IUSxD1hXPxO WBe5lqcozu9LpNDH/brVSzHCSb7vjNGvvSVESDuoiHK8gNlf0v+epy5WYd7CGAgODPvDShGN g3eXuA== Organization: Red Hat In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 07.08.25 01:48, Shakeel Butt wrote: > On Wed, Aug 06, 2025 at 10:14:39PM +0200, David Hildenbrand wrote: >> >> But yeah, whether these "as is" pages are movable or not is a good question >> as well -- in particular when zsmalloc supports page migration and the "as >> is" pages would not. > > By "as is" page, do you mean the page which the reclaim code is trying > to reclaim or the page within zsmalloc on which the content of original > pages are copied as is? I mean whatever the "dst" is here. + if (zswap_save_as_is(comp_ret, dlen, page)) { + comp_ret = 0; + dlen = PAGE_SIZE; + memcpy_from_page(dst, page, 0, dlen); IIUC SJ correctly, in case of zsmalloc "dst" is just the same page that would have stored encrypted data. If that is the case, nothing should change, really. Thanks for clarifying, all! > Most probably you meant the page which the reclaim > code is trying to reclaim. This page is on its way to get freed after > [z]swapout is completed and this patch is not changing any behavior for > that path. Yeah, that's the "page" in the hunk above I guess. -- Cheers, David / dhildenb