From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 6D896258CE9 for ; Mon, 4 Aug 2025 12:50:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754311803; cv=none; b=Znb+W+qI0YBErw2vUaOYb0wlalnjGnPqfPMAdKUQGF7vexf9kmiSaVUuWX5Oj5yYBDf9JyXEdt0PwI962gv1OmIJJn/D4l09fSsp+F/xjABDxMXFd+3s2/eqB6n8G304r6fmLhJymK3GNZfniiZs6F4Yffp1M15/lcO0WMBZqP0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754311803; c=relaxed/simple; bh=cc9bDQvvEzApY/ZAQ1QmRe/Rk3TKihq9tFViG1dVIrU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qbOlpG4CygKirJz8JEn0Kirfu0ZAVXCW+foa2qK0YaDy7Dw32n/JmQVWC3qKctoItWxGmsXqp+doDVRJeeRUXMhyJuhzvyK31CpxhEGpd2EmUkOX/ONqg99X0VUmyAhtq8+iIwJteuiuQx6Tj+ic31BZfkGeUszByWEr/gns0Qs= 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=DqwA+WHR; arc=none smtp.client-ip=170.10.133.124 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="DqwA+WHR" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1754311800; 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=+Xhhf7HOlGHP/+Ew73mE+84gy9qClegxqAGKGx6kZAE=; b=DqwA+WHRxsPud9WsboA3fgNUeLRB9iG5ywPVggVSYpJziFaUWBvFpa2H6nOSPgA/Y1c0fO G4B6lpbP1A+vFgne04OF51006V/YWEx/7IKQSggBLcI5cJmdAHdpz/ZfDuoqnV0zLtSr6U DCuCTitbP4dfxofvKq56WrJ2rJD/588= 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-536-w0GBiNH9PKCoMN9oL-TWdQ-1; Mon, 04 Aug 2025 08:49:57 -0400 X-MC-Unique: w0GBiNH9PKCoMN9oL-TWdQ-1 X-Mimecast-MFC-AGG-ID: w0GBiNH9PKCoMN9oL-TWdQ_1754311796 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-3b8d612996cso1993906f8f.2 for ; Mon, 04 Aug 2025 05:49:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1754311796; x=1754916596; 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=+Xhhf7HOlGHP/+Ew73mE+84gy9qClegxqAGKGx6kZAE=; b=FfLIZUmGaO9cSG0c1CTd8nM99NUrCYJfuQG0P4mDvZjI+MkeiWleLLczICRndTZ5V0 L3C6FSTtU74Q3iZEbTL0HpnA63f1wiwO8b75MtGaE05s5Yr4gOREQIAwxnlTCh7G4kPi fPtQ4KW5WDOYf5cpreR5wH2GYoKG0VU5nOqe+AkXLRer4/7wGeYd1S83QlFpuuqYFbC5 ZYpgz/Ttggq6Vo9eNu9KMZYgHWbcqAExfG/g1piv1gGad/3tCtwptdsNp+VSuMPVaXg5 TyqV/dSMVbc8/+uuuG3YNi1NrldLMRF4Nuy1vSp8jCwR2lgx4OA06pkpKSUSjv5f5qU7 jowA== X-Forwarded-Encrypted: i=1; AJvYcCVYKWjjllycj5i04tw7DAjrgC7GansKu7lKapqofVNmUbu180L7UfRuXXb1PkOKpTfuodDOwpCHZI+3@vger.kernel.org X-Gm-Message-State: AOJu0YxBXbDyEP/Ar1a543peWkTXNOKQAO8hc9QY0iVtbN8Aw0TK2v06 /OISGrZ+a+hkVvrGubmjQIIliTIXdOHrgeaVz+aaAz/Ban2K5qiB7ImtFAy3uUKoCt1cMRytjGp 9yzT7Ljw6NPoPUADDH7+GhdicovD3wdlvVkwkmHCgMZEUPOmB1RJXh5Nd93emD70= X-Gm-Gg: ASbGncuAucf+sgUGYoJKeqjMhNU7037tgGXtcNPAoJDwCFz5kbgiMOfX9PIfOi+1RpF Cg72I3BB5VqJ1Z7fEsAA23b4Ktzc4ASyI0ArbSzyik7uQfcTCnxgrz4MrkxlOZwVJmDnMuAongH ecTO08TsVPt+48BkuB6zauQ/agrs+TQIZi/38evwlE3R5/q78aZpbrt98aRwIUbUIJtVeqxwxIJ oaswCZHa7oep/1xr3HfHPtgPybKkHn9EyZK8R/l2dvwd4GeyDKp7ErsS4/Ql0EvYPFy7Dz9QY2F eKJ8uaq2aYgQd7ene5UzSkYgVSPNXeXPzx96tsrjBB65Lcwyf9IsAgltHgNDRn3ndtAA1xrBDbT gE9hStzujFdEHsbVutkbqkHe7d72+3DwLE1grG72UHb3h6Ecgc9a7FYNWT3jJ+VdUo6w= X-Received: by 2002:a5d:584c:0:b0:3a6:ec1d:1cba with SMTP id ffacd0b85a97d-3b8d947083emr7216529f8f.20.1754311795526; Mon, 04 Aug 2025 05:49:55 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHFXgDt/YpWGgP2V8sWDg7uI7r5JelqiIRnbxs/Y/QppAtTZ4vWQf600coJVI3Z9N9Z5dRAbg== X-Received: by 2002:a5d:584c:0:b0:3a6:ec1d:1cba with SMTP id ffacd0b85a97d-3b8d947083emr7216499f8f.20.1754311795008; Mon, 04 Aug 2025 05:49:55 -0700 (PDT) Received: from ?IPV6:2003:d8:2f0e:2c00:d6bb:8859:fbbc:b8a9? (p200300d82f0e2c00d6bb8859fbbcb8a9.dip0.t-ipconnect.de. [2003:d8:2f0e:2c00:d6bb:8859:fbbc:b8a9]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4589edf56e0sm169284285e9.1.2025.08.04.05.49.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 04 Aug 2025 05:49:54 -0700 (PDT) Message-ID: <77d17dbf-1609-41b1-9244-488d2ce75b33@redhat.com> Date: Mon, 4 Aug 2025 14:49:53 +0200 Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC][PATCH v2 22/29] mm/numa: Register information into Kmemdump To: Eugen Hristev , Michal Hocko Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, tglx@linutronix.de, andersson@kernel.org, pmladek@suse.com, linux-arm-kernel@lists.infradead.org, linux-hardening@vger.kernel.org, corbet@lwn.net, mojha@qti.qualcomm.com, rostedt@goodmis.org, jonechou@google.com, tudor.ambarus@linaro.org References: <20250724135512.518487-1-eugen.hristev@linaro.org> <20250724135512.518487-23-eugen.hristev@linaro.org> <751514db-9e03-4cf3-bd3e-124b201bdb94@redhat.com> <23e7ec80-622e-4d33-a766-312c1213e56b@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 04.08.25 14:29, Eugen Hristev wrote: > > > On 8/4/25 15:18, David Hildenbrand wrote: >> On 04.08.25 13:06, Eugen Hristev wrote: >>> >>> >>> On 8/4/25 13:54, Michal Hocko wrote: >>>> On Wed 30-07-25 16:04:28, David Hildenbrand wrote: >>>>> On 30.07.25 15:57, Eugen Hristev wrote: >>>> [...] >>>>>> Yes, registering after is also an option. Initially this is how I >>>>>> designed the kmemdump API, I also had in mind to add a flag, but, after >>>>>> discussing with Thomas Gleixner, he came up with the macro wrapper idea >>>>>> here: >>>>>> https://lore.kernel.org/lkml/87ikkzpcup.ffs@tglx/ >>>>>> Do you think we can continue that discussion , or maybe start it here ? >>>>> >>>>> Yeah, I don't like that, but I can see how we ended up here. >>>>> >>>>> I also don't quite like the idea that we must encode here what to include in >>>>> a dump and what not ... >>>>> >>>>> For the vmcore we construct it at runtime in crash_save_vmcoreinfo_init(), >>>>> where we e.g., have >>>>> >>>>> VMCOREINFO_STRUCT_SIZE(pglist_data); >>>>> >>>>> Could we similar have some place where we construct what to dump similarly, >>>>> just not using the current values, but the memory ranges? >>>> >>>> All those symbols are part of kallsyms, right? Can we just use kallsyms >>>> infrastructure and a list of symbols to get what we need from there? >>>> >>>> In other words the list of symbols to be completely external to the code >>>> that is defining them? >>> >>> Some static symbols are indeed part of kallsyms. But some symbols are >>> not exported, for example patch 20/29, where printk related symbols are >>> not to be exported. Another example is with static variables, like in >>> patch 17/29 , not exported as symbols, but required for the dump. >>> Dynamic memory regions are not have to also be considered, have a look >>> for example at patch 23/29 , where dynamically allocated memory needs to >>> be registered. >>> >>> Do you think that I should move all kallsyms related symbols annotation >>> into a separate place and keep it for the static/dynamic regions in place ? >> >> If you want to use a symbol from kmemdump, then make that symbol >> available to kmemdump. > > That's what I am doing, registering symbols with kmemdump. > Maybe I do not understand what you mean, do you have any suggestion for > the static variables case (symbols not exported) ? Let's use patch #20 as example: What I am thinking is that you would not include "linux/kmemdump.h" and not leak all of that KMEMDUMP_ stuff in all these files/subsystems that couldn't less about kmemdump. Instead of doing static struct printk_ringbuffer printk_rb_dynamic; You'd do struct printk_ringbuffer printk_rb_dynamic; and have it in some header file, from where kmemdump could lookup the address. So you move the logic of what goes into a dump from the subsystems to the kmemdump core. -- Cheers, David / dhildenb