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 BFF2929898B for ; Wed, 17 Sep 2025 07:03:02 +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=1758092584; cv=none; b=qQx066ELL3UgMrI8jGWxkOxPQdmuaSiYhIPmpX/CUrzH9IxPjnwKNVd0uFiLyyXC4w3iE1AmHaqfjTrPnMFWZDKYJZWcfxvB/QxL/S72VJgaZE0w+ZQip9mRTp0s9aniQMi5WgJbgEyjbtRGckqLUUPV+utdG+KTzVmSV9Jqhls= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758092584; c=relaxed/simple; bh=ko/99fPEHJQwgLb5nCPWVD8uy5wLTxH5KAinDw/smNk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Kgy8kzDPp9xR+7DJPMx/4sRVhyPLbvybDsfx4s2bvT/ajOGrHAtzaF2PB2TqxkmFlo2luOWtKBKusec6n2RJiC1u1rmxHp2GbdDGcoG5E+f5ncwecL/6O2rCOEBZf2Io/ZTEjsSMa6SNz0J7DWVIOhhUNsMgreH4n/mypWYn5b0= 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=Rs/0kaYy; 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="Rs/0kaYy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1758092581; 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=nawTqrlEeqSv7zVujc+JzfalbuSXfxtcl1SSEsQficc=; b=Rs/0kaYyBONENmZNXCGrPlFtnbnQCTHQYIfwwsI5JjDhsUmBfBQ3i79UEqWXu0/s5J/cJY uB+ZVkZr6jizbMQJr0hUm9nsRuPkeyeWPFTgQMnN7lXZQe4AoA+hx5GPqy40vnjCQY1Z5W iP5gPf6ZPcUdGTYxJXO/7vs02ZuJnVk= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-137-7bZNRtnUNS64tOoFeWC6dA-1; Wed, 17 Sep 2025 03:03:00 -0400 X-MC-Unique: 7bZNRtnUNS64tOoFeWC6dA-1 X-Mimecast-MFC-AGG-ID: 7bZNRtnUNS64tOoFeWC6dA_1758092579 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-45b920a0c89so33234375e9.2 for ; Wed, 17 Sep 2025 00:03:00 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758092579; x=1758697379; h=content-transfer-encoding:in-reply-to: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=nawTqrlEeqSv7zVujc+JzfalbuSXfxtcl1SSEsQficc=; b=e9IlZMxsIoo2xnaoxkKKu+Yjq51+4rJv+y3No5x5/tDZpMgghASls0fCe47azlCNJA 9cr6Ar6Z11h3G8onqyelQQTDx3ql73S+M/dC3SW5lCvorA7RyiJi57yEFGQdATyMczqt JvkM2rQQZ97MEW5U0/Ty6CuhOmPONerYG2i1CBxI3ULGtHHMStt9acW3oH3U153nA05K TRCggOd93xSY3E2R2bUtYpPJ5hj3Lym5qVlc4UuDxAc3zkLHKL48ScVyIHlioi1PePvF q+MQXIxdkfgLWxAPWTkrjXw3Xkbqv0wMxFQyPkNtVDJ+iN4K5YBuQl0TweAH/dJP35z6 czEw== X-Forwarded-Encrypted: i=1; AJvYcCXq0xhcNGzwZHahPKAWpY+3nr7VPSZ0G1xfMtGD0NN3ia2J6bfAQ7hulqrQu8N3cOXs5vqtpr1I3gY=@vger.kernel.org X-Gm-Message-State: AOJu0YxqBJz+J/m2NJfx3OL8ZCKIP0xS5fqE3xn7pfa5BoHi8EPnwdB1 TsIFS7pPc/U8eT89U0DRpirM6L+FduqFou647YiQmNWOriqJjK7fTAAjIgcmq0fdwQrTzk6Flne FHSQ0DyMOqnuHkioF6qyRPvVmSml1gX500mvxF1JSgWFogIu4RWREQKh8XQA46w== X-Gm-Gg: ASbGncvjvzpHGl1TYuXaJmPz4Hn8RskNGCWwqusCLGCY+rXrNYYHcL/K3n3u5V3IY1q UIfciPoYYVTG6OP930WICfoocBvi6PoOXkyOfS4o43oTF7edEd0/GxX5jx+Rf+sED9qUTxUzd80 nfEyomPvIQ3YGpbrOG8TJZPrHpQAjpieSZH1NFQdDVzJHuSH6EsUV5I5TLaHzQQYs/Yafjm46O5 FAqkn29DNQ8worGN4q41FKCNKiaJ2rR0ZbpCsCt/QPLKYpckUzvnilPqR8ZxeEt7Ol55Qmb6p/R Q7Mi35x/8sM0i407IATDiLCuLAkkxjMy/p50226pjIkzJszJF9JiYCDTrLX/NyOBrbN675W5bZW T/2iRmPda3grfom9RmL5nvFEMRA3xYlDHMJixZhuH1fE/7KoTxBe5dUbwrDSmR0Bw X-Received: by 2002:a05:600c:1e88:b0:45c:b56c:4183 with SMTP id 5b1f17b1804b1-46205adf753mr8270765e9.18.1758092579140; Wed, 17 Sep 2025 00:02:59 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHCHXqLZgubOsFpSEryXy6qEwTu5TBAMNWT2kDUAPReOb9ESdWMxgF+theDpncx+aIUqSILpQ== X-Received: by 2002:a05:600c:1e88:b0:45c:b56c:4183 with SMTP id 5b1f17b1804b1-46205adf753mr8270405e9.18.1758092578660; Wed, 17 Sep 2025 00:02:58 -0700 (PDT) Received: from ?IPV6:2003:d8:2f27:6d00:7b96:afc9:83d0:5bd? (p200300d82f276d007b96afc983d005bd.dip0.t-ipconnect.de. [2003:d8:2f27:6d00:7b96:afc9:83d0:5bd]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-46137a252fasm23338645e9.7.2025.09.17.00.02.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 17 Sep 2025 00:02:58 -0700 (PDT) Message-ID: <8c3188da-7078-4099-973a-1d0d74db2720@redhat.com> Date: Wed, 17 Sep 2025 09:02:55 +0200 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mm/memory-failure: Support disabling soft offline for HugeTLB pages To: Anshuman Khandual , Kyle Meyer , akpm@linux-foundation.org, corbet@lwn.net, linmiaohe@huawei.com, shuah@kernel.org, tony.luck@intel.com, jane.chu@oracle.com, jiaqiyan@google.com Cc: Liam.Howlett@oracle.com, bp@alien8.de, hannes@cmpxchg.org, jack@suse.cz, joel.granados@kernel.org, laoar.shao@gmail.com, lorenzo.stoakes@oracle.com, mclapinski@google.com, mhocko@suse.com, nao.horiguchi@gmail.com, osalvador@suse.de, rafael.j.wysocki@intel.com, rppt@kernel.org, russ.anderson@hpe.com, shawn.fan@intel.com, surenb@google.com, vbabka@suse.cz, linux-acpi@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org References: 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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit >> + >> + 0 - Enable soft offline >> + 1 - Disable soft offline for HugeTLB pages >> + >> +Supported values:: >> + >> + 0 - Soft offline is disabled >> + 1 - Soft offline is enabled >> + 3 - Soft offline is enabled (disabled for HugeTLB pages) > > This looks very adhoc even though existing behavior is preserved. > > - Are HugeTLB pages the only page types to be considered ? > - How the remaining bits here are going to be used later ? > What I proposed (that could be better documented here) is that all other bits except the first one will be a disable mask when bit 0 is set. 2 - ... but yet disabled for hugetlb 4 - ... but yet disabled for $WHATEVER 8 - ... but yet disabled for $WHATEVERELSE > Also without a bit-wise usage roadmap, is not changing a procfs > interface (ABI) bit problematic ? For now we failed setting it to values that are neither 0 or 1, IIUC set_enable_soft_offline() correctly? So there should not be any problem, or which scenario do you have in mind? -- Cheers David / dhildenb