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 5078215B99F for ; Fri, 9 Aug 2024 07:31:14 +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=1723188676; cv=none; b=RacSS3PO1/M6vWAWvvwQG1pP26j6BWQHOFNg/mKM46NGhvkXBIi835hE1rPYgfFMjwRr1HthtiwZiFrBkBtGUUwvPkt68Sld5CYg2vpP8Z3n4oe6ZaJlZbGKzjuN5Bdif1sPmvKhh/qq84q4m7E7BBjYhwVzXusdN0tA5AfGTzA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723188676; c=relaxed/simple; bh=AI6MQPM9BvoHHnsYc5GqiespVvdfM9oqFd4pjzEMsEI=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=uF4cc9j2SwP1aXauq8dhokzHBNQ1JYDjsMvP6gbK3hxlX7Mv/R5Ct/z8OyI7SPnOPxNpudqRWMwGGep2ofrWUM2W3DUBCGDaHCJZUd/R2KAc0hbRLcKyOhwuardDe9ahcJ6oF79QU/qiaZUOl2/AzI1qpNA6vP8W+PuZ4cFHVk8= 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=SLYuNa0W; 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="SLYuNa0W" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1723188674; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to: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=YnRYGEv/LM94MKGdoZkn/zwYROhxuyklFtJICqYoxoo=; b=SLYuNa0WkKFsaAuHJgyEAKD4Nl4jb5Z+XXua2OyrhJLd4der5ZSlA+bHGL5eFU38SnQPX0 JFtJq1yoCzmIkVvaOgAAeFGoJmbrcqqy1caPsS8oRKsfx0Ej9y1+mTkXeTx1GimWRK3CJ5 1ydHciF5ShbnWLY7b2QnNjR9y4c7JEE= 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-333-roF-nXIOM26oMeAkX8Wpdg-1; Fri, 09 Aug 2024 03:31:10 -0400 X-MC-Unique: roF-nXIOM26oMeAkX8Wpdg-1 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-3687faecea0so791170f8f.2 for ; Fri, 09 Aug 2024 00:31:10 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723188669; x=1723793469; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=YnRYGEv/LM94MKGdoZkn/zwYROhxuyklFtJICqYoxoo=; b=mJDz99lzvgcDM/mrH/aTnUYZAq+uZTkthi235GXuj5MHfHxBUbk4E+uKKiMY9LM7a0 3VXDgkfkWBk08LJj4+7ePklQxeGd9VB5iXGzLNQyDNmlX3GoeivS+MFPOvUMF2sZDLXe oJ5tQjEOzK3p6FTOjdfmNPX/cuJvMEIPPGnFGRweKZe91iMtcuiXjoFFOY6a/2xoONwf 6BsnBpxYL+DNg8b4hdJMI9fOh3JNMjzcHjd+wSjoX5NcZNFvm8QCjESd7RPfiW4bb6iB CM1nXL+tgHrdxHFDLdjD5oH1Xe+xAQ4GuUiendqqIe1urEHqPDsKnHXkTYKLHuhgg5dC 0JxA== X-Forwarded-Encrypted: i=1; AJvYcCXTgbLhEj7Q+bIfYAuMFEIWbVz2ljg1DefuiaSkA0AbTpIJjWo4PRNDwrXmdlDpfIwz/LCkWBb5TPMMqJQBhP4p6TPJa53on1zAX2eW X-Gm-Message-State: AOJu0YzVM8ZagVMpoa38vnIbSvA1ENxcT2AX5QWiezHLNcC3ys5XMUz+ eJ19tvHRjuIt8TvHe/CKT/lXsHsUt9pmuT/0i3+tQR+0CpC8JEToT4o+Z8IKJmttmoYBuVq+WZ3 kO3AZ+gdDopEL9dyOVS3OE8ke5fwf7r2JTlB0XT019nUoj3DX7YoB0H9T9i9tMb7JS8s2xQ== X-Received: by 2002:a5d:5989:0:b0:368:87ca:3d85 with SMTP id ffacd0b85a97d-36d5eb049f3mr422550f8f.29.1723188669365; Fri, 09 Aug 2024 00:31:09 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGNwHH0K++ca2l0Q8K2cg1g53qKHd8GYeGrg0GgdlgP7XKRHsgS5j1+4zw9S1byApVbwUrv+A== X-Received: by 2002:a5d:5989:0:b0:368:87ca:3d85 with SMTP id ffacd0b85a97d-36d5eb049f3mr422529f8f.29.1723188668836; Fri, 09 Aug 2024 00:31:08 -0700 (PDT) Received: from ?IPV6:2003:cb:c71c:4e00:b097:7075:f6ba:300a? (p200300cbc71c4e00b0977075f6ba300a.dip0.t-ipconnect.de. [2003:cb:c71c:4e00:b097:7075:f6ba:300a]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-36d2716e3b3sm4407425f8f.42.2024.08.09.00.31.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 09 Aug 2024 00:31:08 -0700 (PDT) Message-ID: Date: Fri, 9 Aug 2024 09:31:06 +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: [PATCH v4 3/3] mm: don't account memmap per-node To: Pasha Tatashin , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-cxl@vger.kernel.org, cerasuolodomenico@gmail.com, hannes@cmpxchg.org, j.granados@samsung.com, lizhijian@fujitsu.com, muchun.song@linux.dev, nphamcs@gmail.com, rientjes@google.com, rppt@kernel.org, souravpanda@google.com, vbabka@suse.cz, willy@infradead.org, dan.j.williams@intel.com, yi.zhang@redhat.com, alison.schofield@intel.com, yosryahmed@google.com References: <20240808213437.682006-1-pasha.tatashin@soleen.com> <20240808213437.682006-4-pasha.tatashin@soleen.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: <20240808213437.682006-4-pasha.tatashin@soleen.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 08.08.24 23:34, Pasha Tatashin wrote: > Fix invalid access to pgdat during hot-remove operation: > ndctl users reported a GPF when trying to destroy a namespace: > $ ndctl destroy-namespace all -r all -f > Segmentation fault > dmesg: > Oops: general protection fault, probably for > non-canonical address 0xdffffc0000005650: 0000 [#1] PREEMPT SMP KASAN > PTI > KASAN: probably user-memory-access in range > [0x000000000002b280-0x000000000002b287] > CPU: 26 UID: 0 PID: 1868 Comm: ndctl Not tainted 6.11.0-rc1 #1 > Hardware name: Dell Inc. PowerEdge R640/08HT8T, BIOS > 2.20.1 09/13/2023 > RIP: 0010:mod_node_page_state+0x2a/0x110 > > cxl-test users report a GPF when trying to unload the test module: > $ modrpobe -r cxl-test > dmesg > BUG: unable to handle page fault for address: 0000000000004200 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 0 P4D 0 > Oops: Oops: 0000 [#1] PREEMPT SMP PTI > CPU: 0 UID: 0 PID: 1076 Comm: modprobe Tainted: G O N 6.11.0-rc1 #197 > Tainted: [O]=OOT_MODULE, [N]=TEST > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/15 > RIP: 0010:mod_node_page_state+0x6/0x90 > > Currently, when memory is hot-plugged or hot-removed the accounting is > done based on the assumption that memmap is allocated from the same node > as the hot-plugged/hot-removed memory, which is not always the case. > > In addition, there are challenges with keeping the node id of the memory > that is being remove to the time when memmap accounting is actually > performed: since this is done after remove_pfn_range_from_zone(), and > also after remove_memory_block_devices(). Meaning that we cannot use > pgdat nor walking though memblocks to get the nid. > > Given all of that, account the memmap overhead system wide instead. > > For this we are going to be using global atomic counters, but given that > memmap size is rarely modified, and normally is only modified either > during early boot when there is only one CPU, or under a hotplug global > mutex lock, therefore there is no need for per-cpu optimizations. > > Also, while we are here rename nr_memmap to nr_memmap_pages, and > nr_memmap_boot to nr_memmap_boot_pages to be self explanatory that the > units are in page count. > > Reported-by: Yi Zhang > Closes: https://lore.kernel.org/linux-cxl/CAHj4cs9Ax1=CoJkgBGP_+sNu6-6=6v=_L-ZBZY0bVLD3wUWZQg@mail.gmail.com > Reported-by: Alison Schofield > Closes: https://lore.kernel.org/linux-mm/Zq0tPd2h6alFz8XF@aschofie-mobl2/#t > > Fixes: 15995a352474 ("mm: report per-page metadata information") > Signed-off-by: Pasha Tatashin > Tested-by: Dan Williams > --- [...] In general Acked-by: David Hildenbrand Two nits below: > static void free_map_bootmem(struct page *memmap) > diff --git a/mm/vmstat.c b/mm/vmstat.c > index 6f8aa4766f16..ad82c1bf0e63 100644 > --- a/mm/vmstat.c > +++ b/mm/vmstat.c > @@ -1033,6 +1033,23 @@ unsigned long node_page_state(struct pglist_data *pgdat, > } > #endif > > +/* > + * Count number of pages "struct page" and "struct page_ext" consume. > + * nr_memmap_boot: # of pages allocated by boot allocator & not part of MemTotal > + * nr_memmap: # of pages that were allocated by buddy allocator > + */ > +static atomic_long_t nr_memmap_boot, nr_memmap; I *think* the clean and portable way to do it is use ATOMIC_INIT(0) for both. [even though what you have likely works on all archs] > + > +void mod_memmap_boot(long delta) > +{ > + atomic_long_add(delta, &nr_memmap_boot); > +} > + > +void mod_memmap(long delta) > +{ > + atomic_long_add(delta, &nr_memmap); > +} > + Nit picking: (up to you) I'd do it similar to totalram_pages_add(): memmap_pages_add() memmap_boot_pages_add() And call the variables something like static atomic_long_t memmap_pages_boot, memmap_pages; -- Cheers, David / dhildenb