From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) (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 2B5B315B54C; Mon, 14 Apr 2025 23:37:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.21 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744673842; cv=none; b=bdBmH2akiTjzhgpYuFUCascg33LJBB6/SnEHZBoIGDs6kKeSN1KqdKG6GxV4EzFkCi+sDl9dPQIlvKAW/NFzNkaBP0hTwaNAVfp+L8/wTD/Ui62BkJAkTTh7ZZgEEfvSdH38tDEYYwMsGgswdce4W5n3dT4RcU+AO/I8NofAJGg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744673842; c=relaxed/simple; bh=5YhM4OF79FNxcqN9wzVPw1rP4jzYZ6nO9osaCcUX96I=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Cce0CbcHisye0ZSQ9Rlp8NhrQY1Yckw+eaVqe0MrL0EPb+97V+nNPOJkBXjgOAEEhPYi82Fg+o3ZJQlUUpYKdIl6E8QfZm5Gtz+Rr1yV2eniYnvap/nr5G7f3anB9WJ87WSJRYw8DTr8qF8WhZl9N+IXEQAGr2/t0bJZ8NzdzuY= 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=ZIVhF12C; arc=none smtp.client-ip=198.175.65.21 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="ZIVhF12C" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1744673841; x=1776209841; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=5YhM4OF79FNxcqN9wzVPw1rP4jzYZ6nO9osaCcUX96I=; b=ZIVhF12Co1wUPtlBzQrxmkfV9chGewfk5s+9LPjHAbTPT506WMvTrsJW Ua1k067JeQuOXqdCyEK5N678YK+Yv91MRbH3LGJyqGk0Xh16UyMOVTZ5T Ml38JpT72dMAlvO49ZeEjOGJNPXx7K2bJPMTGf1UBIIxIc1O4Ni8ZYg2v OZ6yX8oX4XP8WZPJxOjZQ+I+abNAnojVFb1QGd+p2omlKZ/+rlFwVwWzT LUbdrhG1rxz30i/AHpN6tGpXHOS2fBGht6pQu1Z8dTc8FWKzDbrl2MKFd Ak6uIRQYkQRte6RV0zBIe2+GL+fkdMxVY+gZwVQh9sawgXFgb0jMYPASl g==; X-CSE-ConnectionGUID: iEtniNnaSBiVGc0/GBOt4g== X-CSE-MsgGUID: m7B04P7XRz2QEUXDwMkEPw== X-IronPort-AV: E=McAfee;i="6700,10204,11403"; a="46073688" X-IronPort-AV: E=Sophos;i="6.15,213,1739865600"; d="scan'208";a="46073688" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2025 16:37:20 -0700 X-CSE-ConnectionGUID: bsGeB27oRWy6llquppN4fg== X-CSE-MsgGUID: U2n0qvsURUSz5qJhXj38ig== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,213,1739865600"; d="scan'208";a="153135023" Received: from johunt-mobl9.ger.corp.intel.com (HELO [10.124.222.39]) ([10.124.222.39]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2025 16:37:19 -0700 Message-ID: Date: Mon, 14 Apr 2025 16:37:19 -0700 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] x86/tracing: introduce enter/exit tracepoint pairs for page faults To: Junxuan Liao , linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , "Paul E. McKenney" References: <214abd94-7fb3-4515-a1ae-a60abe81af88@intel.com> <41e7d947-d59f-41a9-a540-d3c07e4678c4@cs.wisc.edu> 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: <41e7d947-d59f-41a9-a540-d3c07e4678c4@cs.wisc.edu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/14/25 16:22, Junxuan Liao wrote: > On 4/14/25 6:14 PM, Junxuan Liao wrote: >> Do people find separate user/kernel tracepoints useful? For me, I can >> check regs in eBPF tracing code instead. > I think it might be good to add a field to the tracepoints to indicate > whether it's in user space or not. Sounds sane to me. Doing something like this: TP_STRUCT__entry( __field( unsigned long, address ) __field( unsigned long, ip ) + __field( bool , user_mode) __field( unsigned long, error_code ) ), TP_fast_assign( __entry->address = address; __entry->ip = regs->ip; + __entry->user_mode = user_mode(regs); __entry->error_code = error_code; ), seems highly superior to having two sets of tracepoints and static keys.