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 6340D1B4F04 for ; Thu, 30 Jan 2025 09:28:06 +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=1738229290; cv=none; b=moFzsiz/MBdctQ+hNYtWlQ8gegb5Cjxu7nZCCV5614zDMJbMWC8wrUJ4wPr/0fleAMovmEdJW3WPbiN3LfnzsXCjGE2McwxZF+CK3hVw4jN10Cl5IgSFEByDedyZLh5NgYz0X+tULQUAiSro1lbqzouiBC/UEpQgmZcvaTIIEow= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738229290; c=relaxed/simple; bh=B1owPnV04u47VK/53oPxspH8yMFlCE/sNbHLLUa/wjE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nF3WpsevZhxyDxUi+GxYHFH3EEH0V2TWx0sG6zX6RpRh0Vhvou8ljYZkL0zOryS4z58k1QlFq8UeuJnqMXI978Xf+r9YTzndK/zJlb24kixMGCSAvnuaPmqACU01cjOCliUb3PcBeheuzWq/pp+4yyxS/90YLyyFyZvLF5haxOo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=f2UF8e64; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="f2UF8e64" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1738229286; 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=8a2uS8Wdref7tlZzoBWWMkEGl9+CP1s01bTe+snzNOI=; b=f2UF8e647DvRqz9PG6MNubc9gGF2U5ORIooh+QrwHTxvhxyXizZKbl2i/YoY6hsCmT+Zyf UqYLhok80d03SiqcFwPP5WtQmIneWn/EBGrBjet2DUtoDxnK3G8Duj2aX004e0Dr+BXhVc oXjPQgF2BqrDs/WLZOe2X0/QxhJOk5k= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-501-FrLu-g8DP2mfr7w8RK2qXQ-1; Thu, 30 Jan 2025 04:28:04 -0500 X-MC-Unique: FrLu-g8DP2mfr7w8RK2qXQ-1 X-Mimecast-MFC-AGG-ID: FrLu-g8DP2mfr7w8RK2qXQ Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-4362f893bfaso2536185e9.1 for ; Thu, 30 Jan 2025 01:28:04 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738229283; x=1738834083; 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=8a2uS8Wdref7tlZzoBWWMkEGl9+CP1s01bTe+snzNOI=; b=s5xpI6C9aGG1SaQih6AxuZ2dscnYuFfxjhbbCWm1WZVqRzvPuZnvx4117QD3OPJjau croobGvVF7p6G2lspz/dlBlfhrl/MghYZ50oCzuWBqt8jaom54ACJsNF5Z4U9LueLX/C gBicfCPwqOSiCBjcWo5ankTMyRSJvm83bsmSYadUgJtiV1WCBam8DyimUaIYexPYd2vg O7YpI4sFgQy0ulNWwLYvwXERE8TQVQBpwbcTuE500ZciJWNMASTyYF9gIowOGfOUTgQ3 5kXWrn21qCi/NRwEOIRcdaRJQksQ3mZRKfgTlqSiYzFZv1GT+SXnk5IX5xRj85ZF5voF 0zOw== X-Gm-Message-State: AOJu0Yy+KplIBMtR+GAUWXWvu6+jQwXYs5VWmNMFfDiz7luNTQBHm39B 4QIG4mvxQOu+HMD1O5D6eDvrCxGrYjtbYrHtzqePpWwBM51iuxArCJa/6s/pw4Svxulfm0HdwFP GhNw8/KXQZz3JSU57/kU/HGwposuLNL/zDFkn27o5KxE1aZvCvPNVa0trzo4Cgg== X-Gm-Gg: ASbGnct62HNPUnhZlxVokrXvMZzNCzw4xVp7T9+obQqghUeOgnxa/A27GZobF59unax 1QPS+qca6wvKmaIRqGBHez4vy7eOSXTPSopwG8clEl3XGcroYh98EQLE4uvuS7euwcvOte7vU24 h2OPnsScOhNQbkH+FIq5MXnmt2p2gQGIxBWBuDVLb/F0U6HI2ffaWb2cZXD+QkJsMb+1ZCvHr6J QDLCFnROGctWhwTPoIOttokZ9bPOIW8YU7wU4QhKlCpy0qHMUputoxDl4pXmy38pyUcKioFWAD3 FeCuwIdwnd/PKL/KD9wXHLf5dqzPi6RV+922wGDnx3Tm X-Received: by 2002:a05:600c:1e21:b0:434:fec5:4ef5 with SMTP id 5b1f17b1804b1-438dc3c3287mr61472935e9.14.1738229283571; Thu, 30 Jan 2025 01:28:03 -0800 (PST) X-Google-Smtp-Source: AGHT+IEVv9sk0PSOraNHCtifr1n2WcH7tWWGxI7ZU8RxZfSrxnyJnI+Uc52lsNZOLN2ReMg84oUVgA== X-Received: by 2002:a05:600c:1e21:b0:434:fec5:4ef5 with SMTP id 5b1f17b1804b1-438dc3c3287mr61472565e9.14.1738229283230; Thu, 30 Jan 2025 01:28:03 -0800 (PST) Received: from ?IPV6:2a01:599:904:96e0:a245:aa9f:6c57:eb41? ([2a01:599:904:96e0:a245:aa9f:6c57:eb41]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-438e23d42d4sm17055365e9.6.2025.01.30.01.28.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Jan 2025 01:28:02 -0800 (PST) Message-ID: Date: Thu, 30 Jan 2025 10:28:00 +0100 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: [PATCH v1 2/4] mm/mmu_notifier: drop owner from MMU_NOTIFY_EXCLUSIVE To: Alistair Popple Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org, nouveau@lists.freedesktop.org, Andrew Morton , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Jonathan Corbet , Alex Shi , Yanteng Si , Karol Herbst , Lyude Paul , Danilo Krummrich , David Airlie , Simona Vetter , "Liam R. Howlett" , Lorenzo Stoakes , Vlastimil Babka , Jann Horn , Pasha Tatashin , Peter Xu , Jason Gunthorpe References: <20250129115803.2084769-1-david@redhat.com> <20250129115803.2084769-3-david@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/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: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 30.01.25 06:34, Alistair Popple wrote: > On Wed, Jan 29, 2025 at 12:58:00PM +0100, David Hildenbrand wrote: >> We no longer get a MMU_NOTIFY_EXCLUSIVE on conversion with the owner set >> that one has to filter out: if there already *is* a device-exclusive >> entry (e.g., other device, we don't have that information), GUP will >> convert it back to an ordinary PTE and notify via >> remove_device_exclusive_entry(). > > What tree is this against? I tried applying to v6.13 and Linus current master > but neither applied cleanly. See the cover letter. This is on top of the fixes series, which is based on mm-unstable from yesterday. > >> Signed-off-by: David Hildenbrand >> --- >> drivers/gpu/drm/nouveau/nouveau_svm.c | 6 +----- >> include/linux/mmu_notifier.h | 4 +--- >> include/linux/rmap.h | 2 +- >> lib/test_hmm.c | 2 +- >> mm/rmap.c | 3 +-- >> 5 files changed, 5 insertions(+), 12 deletions(-) >> >> diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c >> index 39e3740980bb..4758fee182b4 100644 >> --- a/drivers/gpu/drm/nouveau/nouveau_svm.c >> +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c >> @@ -510,10 +510,6 @@ static bool nouveau_svm_range_invalidate(struct mmu_interval_notifier *mni, >> struct svm_notifier *sn = >> container_of(mni, struct svm_notifier, notifier); >> >> - if (range->event == MMU_NOTIFY_EXCLUSIVE && >> - range->owner == sn->svmm->vmm->cli->drm->dev) >> - return true; > > I think this will cause a live-lock because make_device_exclusive_range() > will call the notifier which without the filtering will increment the sequence > count and cause endless retries of the loop in nouveau_atomic_range_fault(). > The notifier needs to be able to figure out if it was called in response to > something this thread did (ie. make_device_exclusive_range) and can therefore > ignore the invalidation, or from some other thread. Yes, as discussed in the other patch, this must stay to inform secondary MMUs about the conversion *to* device exclusive. > > Looking at hmm_test I see that doesn't use the sequence counter to ensure > the PTE remains valid whilst it is mapped. I think that is probably wrong, so > apologies if that lead you astray. Yes, the hmm_test does not completely follow the same model the nouveau implementation does; so it might not be completely correct. -- Cheers, David / dhildenb