From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 BC5A928C867; Fri, 1 Aug 2025 16:24:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754065486; cv=none; b=bSt61bKTxHBB9l8D7iJB5duHSZJ1qkJvhbNg/puRxqRShuigM4NZcXGwstPrQ4fGu7/1vPkC5wQWUOoMoWwQq+N0xTiR5u5plN66KFumYXePsh6O+Jw/n78SvWXdWNieSbqBaRd1++wSUCq3CIQ6tTcnWJZtYPmBV8ZWPf/yX34= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754065486; c=relaxed/simple; bh=L65KpuFKY95nCG2r6EZ5ou3o2QbJ7zPptgi7NLjCcqo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dvVjTcp0a+biCJI5ycq2B5VCQaCW7mdTSwGcDXtybzPBCs5zP1G1uHCxNUK7UjKp2gHb84atwTZvIkIdKuJ3VSZiPxgP+MgVXfsP4zf/1t1tLyGX6CNvFGth+1wLRNhw88JOAJ04rzEMEuGU5apSOpgeCgEp59dP25pUVt1Wlis= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Q0hnKkGb; arc=none smtp.client-ip=198.175.65.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Q0hnKkGb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1754065485; x=1785601485; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=L65KpuFKY95nCG2r6EZ5ou3o2QbJ7zPptgi7NLjCcqo=; b=Q0hnKkGbYdH1raZXPTFokTTzpn8zTjLcgfvxXAynk4puvDPV1Kxwrnik 8aDUrDkxBql5/V/mq5zEVH+3K/vMpPLBZaT5IaLfElOQV5UpD8Ui4CUSk YMKBn2jfmlql4cIIfsfmWN9GURGIe41BFLBid3rpVQXvRvd+XgGl8RAmu T/AYpuKkK/GfYB576cu74sVuYQb2yaQNbxQel4VyNz6GvwaEu7wGqYG+T 2yYQmRmANSJzvwHzXYdyOW/Dgm1aQx3sI+HpT2kKBQfMYxf8cb8p761Lm DSSzG+m3uKHZOHW9GSU7j0sbrdgHULP1BSUmr7tBX8NHdOOTzNV/mc98b g==; X-CSE-ConnectionGUID: ntglfKP+QOmQDjhCA+4ZNQ== X-CSE-MsgGUID: sRy+7lcATPCdWoum6VzPgQ== X-IronPort-AV: E=McAfee;i="6800,10657,11508"; a="73875458" X-IronPort-AV: E=Sophos;i="6.17,255,1747724400"; d="scan'208";a="73875458" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Aug 2025 09:24:44 -0700 X-CSE-ConnectionGUID: pkbxLzpfRCe64/Km9bHfPg== X-CSE-MsgGUID: RSAUU9XwRUSz69D2Ut2enw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.17,255,1747724400"; d="scan'208";a="163949953" Received: from aschofie-mobl2.amr.corp.intel.com (HELO [10.125.109.249]) ([10.125.109.249]) by orviesa008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Aug 2025 09:24:44 -0700 Message-ID: <0c045f1b-44d0-430c-9e8a-58b65dd84453@intel.com> Date: Fri, 1 Aug 2025 09:24:43 -0700 Precedence: bulk X-Mailing-List: linux-edac@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4] vmcoreinfo: Track and log recoverable hardware errors To: Breno Leitao Cc: "Rafael J. Wysocki" , Len Brown , James Morse , Tony Luck , Borislav Petkov , Robert Moore , Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Hanjun Guo , Mauro Carvalho Chehab , Mahesh J Salgaonkar , Oliver O'Halloran , Bjorn Helgaas , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, acpica-devel@lists.linux.dev, osandov@osandov.com, xueshuai@linux.alibaba.com, konrad.wilk@oracle.com, linux-edac@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, kernel-team@meta.com, osandov@fb.com References: <20250801-vmcore_hw_error-v4-1-fa1fe65edb83@debian.org> <85663f65-d746-4e2c-b8a6-d594d9d0ba42@intel.com> From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzUVEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gKEludGVsIFdvcmsgQWRkcmVzcykgPGRhdmUuaGFuc2VuQGludGVs LmNvbT7CwXgEEwECACIFAlQ+9J0CGwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEGg1 lTBwyZKwLZUP/0dnbhDc229u2u6WtK1s1cSd9WsflGXGagkR6liJ4um3XCfYWDHvIdkHYC1t MNcVHFBwmQkawxsYvgO8kXT3SaFZe4ISfB4K4CL2qp4JO+nJdlFUbZI7cz/Td9z8nHjMcWYF IQuTsWOLs/LBMTs+ANumibtw6UkiGVD3dfHJAOPNApjVr+M0P/lVmTeP8w0uVcd2syiaU5jB aht9CYATn+ytFGWZnBEEQFnqcibIaOrmoBLu2b3fKJEd8Jp7NHDSIdrvrMjYynmc6sZKUqH2 I1qOevaa8jUg7wlLJAWGfIqnu85kkqrVOkbNbk4TPub7VOqA6qG5GCNEIv6ZY7HLYd/vAkVY E8Plzq/NwLAuOWxvGrOl7OPuwVeR4hBDfcrNb990MFPpjGgACzAZyjdmYoMu8j3/MAEW4P0z F5+EYJAOZ+z212y1pchNNauehORXgjrNKsZwxwKpPY9qb84E3O9KYpwfATsqOoQ6tTgr+1BR CCwP712H+E9U5HJ0iibN/CDZFVPL1bRerHziuwuQuvE0qWg0+0SChFe9oq0KAwEkVs6ZDMB2 P16MieEEQ6StQRlvy2YBv80L1TMl3T90Bo1UUn6ARXEpcbFE0/aORH/jEXcRteb+vuik5UGY 5TsyLYdPur3TXm7XDBdmmyQVJjnJKYK9AQxj95KlXLVO38lczsFNBFRjzmoBEACyAxbvUEhd GDGNg0JhDdezyTdN8C9BFsdxyTLnSH31NRiyp1QtuxvcqGZjb2trDVuCbIzRrgMZLVgo3upr MIOx1CXEgmn23Zhh0EpdVHM8IKx9Z7V0r+rrpRWFE8/wQZngKYVi49PGoZj50ZEifEJ5qn/H Nsp2+Y+bTUjDdgWMATg9DiFMyv8fvoqgNsNyrrZTnSgoLzdxr89FGHZCoSoAK8gfgFHuO54B lI8QOfPDG9WDPJ66HCodjTlBEr/Cwq6GruxS5i2Y33YVqxvFvDa1tUtl+iJ2SWKS9kCai2DR 3BwVONJEYSDQaven/EHMlY1q8Vln3lGPsS11vSUK3QcNJjmrgYxH5KsVsf6PNRj9mp8Z1kIG qjRx08+nnyStWC0gZH6NrYyS9rpqH3j+hA2WcI7De51L4Rv9pFwzp161mvtc6eC/GxaiUGuH BNAVP0PY0fqvIC68p3rLIAW3f97uv4ce2RSQ7LbsPsimOeCo/5vgS6YQsj83E+AipPr09Caj 0hloj+hFoqiticNpmsxdWKoOsV0PftcQvBCCYuhKbZV9s5hjt9qn8CE86A5g5KqDf83Fxqm/ vXKgHNFHE5zgXGZnrmaf6resQzbvJHO0Fb0CcIohzrpPaL3YepcLDoCCgElGMGQjdCcSQ+Ci FCRl0Bvyj1YZUql+ZkptgGjikQARAQABwsFfBBgBAgAJBQJUY85qAhsMAAoJEGg1lTBwyZKw l4IQAIKHs/9po4spZDFyfDjunimEhVHqlUt7ggR1Hsl/tkvTSze8pI1P6dGp2XW6AnH1iayn yRcoyT0ZJ+Zmm4xAH1zqKjWplzqdb/dO28qk0bPso8+1oPO8oDhLm1+tY+cOvufXkBTm+whm +AyNTjaCRt6aSMnA/QHVGSJ8grrTJCoACVNhnXg/R0g90g8iV8Q+IBZyDkG0tBThaDdw1B2l asInUTeb9EiVfL/Zjdg5VWiF9LL7iS+9hTeVdR09vThQ/DhVbCNxVk+DtyBHsjOKifrVsYep WpRGBIAu3bK8eXtyvrw1igWTNs2wazJ71+0z2jMzbclKAyRHKU9JdN6Hkkgr2nPb561yjcB8 sIq1pFXKyO+nKy6SZYxOvHxCcjk2fkw6UmPU6/j/nQlj2lfOAgNVKuDLothIxzi8pndB8Jju KktE5HJqUUMXePkAYIxEQ0mMc8Po7tuXdejgPMwgP7x65xtfEqI0RuzbUioFltsp1jUaRwQZ MTsCeQDdjpgHsj+P2ZDeEKCbma4m6Ez/YWs4+zDm1X8uZDkZcfQlD9NldbKDJEXLIjYWo1PH hYepSffIWPyvBMBTW2W5FRjJ4vLRrJSUoEfJuPQ3vW9Y73foyo/qFoURHO48AinGPZ7PC7TF vUaNOTjKedrqHkaOcqB185ahG2had0xnFsDPlx5y In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/1/25 08:13, Breno Leitao wrote: > Hello Dave, > > On Fri, Aug 01, 2025 at 07:52:17AM -0700, Dave Hansen wrote: >> On 8/1/25 05:31, Breno Leitao wrote: >>> Introduce a generic infrastructure for tracking recoverable hardware >>> errors (HW errors that are visible to the OS but does not cause a panic) >>> and record them for vmcore consumption. >> ... >> >> Are there patches for the consumer side of this, too? Or do humans >> looking at crash dumps have to know what to go digging for? >> >> In either case, don't we need documentation for this new ABI? > > I have considered this, but the documentation for vmcoreinfo > (admin-guide/kdump/vmcoreinfo.rst) solely documents what is explicitly > exposed by vmcore, which differs from the nature of these counters. > > Where would be a good place to document it? I'm not picky. But you also didn't quite answer the question I was asking. Is this new data for humans or machines to read? >>> @@ -1690,6 +1691,9 @@ noinstr void do_machine_check(struct pt_regs *regs) >>> } >>> >>> out: >>> + /* Given it didn't panic, mark it as recoverable */ >>> + hwerr_log_error_type(HWERR_RECOV_MCE); >>> + >> >> Does "MCE" mean anything outside of x86? > > AFAIK this is a MCE concept. I'm not really sure what that response means. There are two problems here. First is that HWERR_RECOV_MCE is defined in arch-generic code, but it may never get used by anything other than x86 when CONFIG_X86_MCE. That also completely wastes space in your data structure when HWERR_RECOV_MCE=n. Not a huge deal as-is, but it's still a bit sloppy and wasteful. ... >>> + hwerr_data[src].count++; >>> + hwerr_data[src].timestamp = ktime_get_real_seconds(); >>> +} >>> +EXPORT_SYMBOL_GPL(hwerr_log_error_type); >> >> I'd also love to hear more about _actual_ users of this. Surely, someone >> hit a real world problem and thought this would be a nifty solution. Who >> was that? What problem did they hit? How does this help them? > > Yes, this has been extensively discussed in the very first version of > the patch. Borislav raised the same question, which was discussed in the > following link: > > https://lore.kernel.org/all/20250715125327.GGaHZPRz9QLNNO-7q8@fat_crate.local/ When someone raises a concern, we usually try to alleviate the concern in a way that is self-contained in the next posting. A cover letter with a full explanation would be one place to put the reasoning, for example. But expecting future reviewers to plod through all the old threads isn't really feasible.