From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 703DEC3ABAC for ; Fri, 2 May 2025 14:37:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=03s7BNMboOs8da03K5C/ory0ZO/Z476bbMSoTGtndmI=; b=SMn1GSqKMX28a9 dk1visxeX0OsQkANNG6eDT9l4UXbY1HiOh0aWCLxF6KUm5DlYoJFHhsuXiY7dLTaIHQLZYX2hnDOt F5g/KjUPBp7rXqW5KvDLnMFewHy2BTvWlEfwBxwGkWpy+sHH7I9U3vdI/OLJ7r7BHaUSd+FwSUEmc QWhW9gu7a+v+Y6czh25H3nQcFX24XLESQSWh1HRoi5DuQk6OsnqpGJ7clG06kABPRMeHaVJxVPyXc HxgiSdefIpdpoDGABbt0Ll9JoVQm8NxdGQEmIK3n7x1UtSei2w2HCzXNKiP9wJcNH5Kz866U+P0Aa l677fsaHIBarrlW5uJFg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uArWE-00000002DFR-3fHa; Fri, 02 May 2025 14:37:38 +0000 Received: from mgamail.intel.com ([198.175.65.19]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uArSn-00000002Cgd-2ShX; Fri, 02 May 2025 14:34:07 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1746196446; x=1777732446; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=6xpTcm5i9h8w6CwoFRxZPxtoKJJ3BBCKGnmNa7Z2kh4=; b=Npe5tFXNWCE2ydv1+lpRhtikkivi/XAwMXnMIKPnPQ5wuM+WFF8b4lqU PXfISgifALZahW+OrIsEOUfaVmUCVxLtVp0+KxI1O3P2oiQSw6k882tyq g4PfyRHulvqm9LF0l+I1uKpfeRX2D0+kjDDyy1u6m+7LK7zR/gU3/f7zA 2q9aWVRUMxxxu2OtWQR4o+uXLuGHP1nICenJJW7H+ZtArzbjGcUjsq4Cg VyaT5fn+pxkTqrGHSggUb08MdL8nwgkjgS8dZ9HZsFKNkxz4mYpoKoLFf b3KuGJ/wZkkcKVuXroOyTpLCDFoqcjecZjcKJotUuF848QheFn2yFf9le Q==; X-CSE-ConnectionGUID: PILMhY7FRMa7vnlhX/jIHg== X-CSE-MsgGUID: CYgrstfTRIivPbMLjKYt0A== X-IronPort-AV: E=McAfee;i="6700,10204,11421"; a="47762482" X-IronPort-AV: E=Sophos;i="6.15,256,1739865600"; d="scan'208";a="47762482" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 May 2025 07:34:04 -0700 X-CSE-ConnectionGUID: VxHvVA4GR1yhOEAvPb47UQ== X-CSE-MsgGUID: rx5pPAMZTRORyTUWVz/hDw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,256,1739865600"; d="scan'208";a="135634956" Received: from bjrankin-mobl3.amr.corp.intel.com (HELO [10.124.220.153]) ([10.124.220.153]) by orviesa008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 May 2025 07:33:59 -0700 Message-ID: <6c44fa0e-28ed-400e-aaf2-e0e0720d3811@intel.com> Date: Fri, 2 May 2025 07:33:55 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 00/25] context_tracking,x86: Defer some IPIs until a user->kernel transition To: Peter Zijlstra Cc: Steven Rostedt , Valentin Schneider , linux-kernel@vger.kernel.org, virtualization@lists.linux.dev, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, linux-perf-users@vger.kernel.org, kvm@vger.kernel.org, linux-arch@vger.kernel.org, linux-modules@vger.kernel.org, linux-trace-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-hardening@vger.kernel.org, linux-kselftest@vger.kernel.org, bpf@vger.kernel.org, Juri Lelli , Marcelo Tosatti , Yair Podemsky , Josh Poimboeuf , Daniel Wagner , Petr Tesarik , Nicolas Saenz Julienne , Frederic Weisbecker , "Paul E. McKenney" , Dave Hansen , Sean Christopherson , Juergen Gross , Ajay Kaher , Alexey Makhalov , Broadcom internal kernel review list , Russell King , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Pawan Gupta , Paolo Bonzini , Arnd Bergmann , Jason Baron , Ard Biesheuvel , Luis Chamberlain , Petr Pavlu , Sami Tolvanen , Daniel Gomez , Naveen N Rao , Anil S Keshavamurthy , "David S. Miller" , Masami Hiramatsu , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman , Kees Cook , Shuah Khan , Masahiro Yamada , Alice Ryhl , Miguel Ojeda , "Mike Rapoport (Microsoft)" , Rong Xu , Rafael Aquini , Song Liu , Andrii Nakryiko , Dan Carpenter , Brian Gerst , "Kirill A. Shutemov" , Benjamin Berg , Vishal Annapurve , Randy Dunlap , John Stultz , Tiezhu Yang References: <20250429113242.998312-1-vschneid@redhat.com> <20250430132047.01d48647@gandalf.local.home> <019f6713-cfbd-466b-8fb5-dcd982cf8644@intel.com> <20250502112216.GZ4198@noisy.programming.kicks-ass.net> 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: <20250502112216.GZ4198@noisy.programming.kicks-ass.net> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250502_073405_656109_32F666E3 X-CRM114-Status: GOOD ( 23.40 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org T24gNS8yLzI1IDA0OjIyLCBQZXRlciBaaWpsc3RyYSB3cm90ZToKPiBPbiBXZWQsIEFwciAzMCwg MjAyNSBhdCAxMTowNzozNUFNIC0wNzAwLCBEYXZlIEhhbnNlbiB3cm90ZToKPiAKPj4gQm90aCBB TUQgYW5kIEludGVsIGhhdmUgaGFyZHdhcmUgdG8gZG8gaXQuIEFSTSBDUFVzIGRvIGl0IHRvbywg SSB0aGluay4KPj4gWW91IGNhbiBnbyBidXkgdGhlIEludGVsIGhhcmR3YXJlIG9mZiB0aGUgc2hl bGYgdG9kYXkuCj4gVG8gYmUgZmFpciwgdGhlIEludGVsIFJBUiB0aGluZyBpcyBwcmV0dHkgaG9y cmlmaWMg8J+ZgSBEZWZpbml0ZWx5Cj4gc3ViLXBhciBjb21wYXJlZCB0byB0aGUgQU1EIGFuZCBB Uk0gdGhpbmdzLgo+IAo+IEZ1cnRoZXJtb3JlLCB0aGUgcGFwZXIgc3RhdGVzIGl0IGlzIGEgdWFy Y2ggZmVhdHVyZSBmb3IgU1BSIHdpdGggbm8KPiBndWFyYW50ZWUgZnV0dXJlIHVhcmNocyB3aWxs IGdldCBpdCAoYW5kIHRvIGJlIGZhaXIsIEknZCBwcmVmZXIgaXQgaWYKPiB0aGV5IGRpZG4ndCku CgpJIGRvbid0IHRoaW5rIGFueSBvZiB0aGF0IGlzIHNldCBpbiBzdG9uZSwgZndpdy4gSXQgc2hv dWxkIGJlIGVudGlyZWx5CnBvc3NpYmxlIHRvIG9idGFpbiBhIGxvbmdlciBwcm9taXNlIGFib3V0 IGl0cyBhdmFpbGFiaWxpdHkuCgpPciBhc2sgdGhhdCBBTUQgYW5kIEludGVsIHB1dCB0aGVpciBo ZWFkcyB0b2dldGhlciBpbiB0aGVpciBmYW5jeSBuZXcKeDg2IGFkdmlzb3J5IGdyb3VwIGFuZCBm aWd1cmUgb3V0IGEgc2luZ2xlIHdheSBmb3J3YXJkLiBJZiB5b3UncmUgcmlnaHQKdGhhdCBSQVIg c3RpbmtzIGFuZCBJTlZMUEdCIHJvY2tzLCB0aGVuIGl0J2xsIGJlIGFuIGVhc3kgdGhpbmcgdG8g YWR2aXNlLgoKPiBGdXJ0aGVybW9yZSwgSSBzdXNwZWN0IGl0IHdpbGwgYWN0dWFsbHkgYmUgc2xv d2VyIHRoYW4gSVBJcyBmb3IgYW55dGhpbmcKPiB3aXRoIG1vcmUgdGhhbiA2NCBsb2dpY2FsIENQ VXMgZHVlIHRvIHJlZHVjZWQgcGFyYWxsZWxpc20uCgpNYXliZSBteSBicmFpbiBpcyBjcnVzdHkg YW5kIEkgbmVlZCB0byBnbyBiYWNrIGFuZCByZWFkIHRoZSBzcGVjLCBidXQgSQpyZW1lbWJlciBS QVIgdXNpbmcgdGhlIG5vcm1hbCBvbGQgQVBJQyBwcm9ncmFtbWluZyB0aGF0IG5vcm1hbCBvbGQg VExCCmZsdXNoIElQSXMgdXNlLiBTbyB0aGV5IGhhdmUgc2ltaWxhciByZXN0cmljdGlvbnMuIElm IGl0J3MgaW5lZmZpY2llbnQKdG8gcHJvZ3JhbSBhIHdpZGUgSVBJLCBpdCdzIGFsc28gaW5lZmZp Y2llbnQgdG8gcHJvZ3JhbSBhIFJBUiBvcGVyYXRpb24uClNvIHRoZSAodGhlb3JldGljYWwpIHBy byBpcyB0aGF0IHlvdSBwcm9ncmFtIGl0IGxpa2UgYW4gSVBJIGFuZCBpdCBzbG90cwppbnRvIHRo ZSBJUEkgY29kZSBmYWlybHkgZWFzaWx5LiBCdXQgdGhlIGNvbiBpcyB0aGF0IGl0IGhhcyB0aGUg c2FtZQpsaW1pdGF0aW9ucyBhcyBJUElzLgoKSSB3YXMgYWN0dWFsbHkgY29uY2VybmVkIHRoYXQg SU5WTFBHQiB3b24ndCBiZSBzY2FsYWJsZS4gU2luY2UgaXQKZG9lc24ndCBoYXZlIHRoZSBhYmls aXR5IHRvIHRhcmdldCBzcGVjaWZpYyBDUFVzIGluIHRoZSBJU0EsIGl0CmZ1bmRhbWVudGFsbHkg bmVlZCB0byBlaXRoZXIgaGF2ZSBhIG1lY2hhbmlzbSB0byByZWFjaCBhbGwgQ1BVcywgb3Igc29t ZQp3YXkgdG8ga25vdyB3aGljaCBUTEIgZW50cmllcyBlYWNoIENQVSBtaWdodCBoYXZlLgoKTWF5 YmUgQU1EIGhhcyBzb21ldGhpbmcgc3VwZXIgZHVwZXIgY2xldmVyIHRvIGxpbWl0IHRoZSBicm9h ZGNhc3Qgc2NvcGUuCkJ1dCBpZiB0aGV5IGRvbid0LCB0aGVuIGEgc21hbGwgcmFuZ2UgZmx1c2gg b24gYSBzbWFsbCBudW1iZXIgb2YgQ1BVcwptaWdodCBlbmQgdXAgYmVpbmcgcHJldHR5IGV4cGVu c2l2ZSwgcmVsYXRpdmVseS4KCkkgZG9uJ3QgdGhpbmsgdGhpcyBpcyBhIGJpZyBwcm9ibGVtIGlu IFJpaydzIHNlcmllcyBiZWNhdXNlIGhlIGhhZCBhCmZsb29yIG9uIHRoZSBzaXplIG9mIHByb2Nl c3NlcyB0aGF0IGdldCBJTlZMUEdCIGFwcGxpZWQuIEFsc28sIGlmIGl0CnR1cm5zIG91dCB0byBi ZSBhIHByb2JsZW0sIGl0J3MgZGlydCBzaW1wbGUgdG8gcmV2ZXJ0IGJhY2sgdG8gSVBJcyBmb3IK cHJvYmxlbWF0aWMgVExCIGZsdXNoZXMuCgpCdXQgSSBhbSBkZWVwbHkgY3VyaW91cyBob3cgdGhl IHN5c3RlbSB3aWxsIGJlaGF2ZSBpZiB0aGVyZSBhcmUgYQpib2F0bG9hZCBvZiBwcm9jZXNzZXMg ZG9pbmcgbW9kZXN0bHktc2l6ZWQgSU5WTFBHQnMgdGhhdCBvbmx5IGFwcGx5IHRvIGEKaGFuZGZ1 bCBvZiBDUFVzIG9uIGEgdmVyeSBsYXJnZSBzeXN0ZW0uCgpBTUQgYW5kIEludGVsIGNhbWUgYXQg dGhpcyBmcm9tIHZlcnkgZGlmZmVyZW50IGFuZ2xlcyAoZ28gZmlndXJlKS4gVGhlCmRlc2lnbnMg YXJlIHByaW9yaXRpemluZyBkaWZmZXJlbnQgdGhpbmdzIGZvciBzdXJlLiBJIGNhbid0IHdhaXQg dG8gc2VlCmJvdGggb2YgdGhlbSBmaWdodGluZyBpdCBvdXQgdW5kZXIgcmVhbCB3b3JrbG9hZHMu CgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpsaW51eC1y aXNjdiBtYWlsaW5nIGxpc3QKbGludXgtcmlzY3ZAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8v bGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LXJpc2N2Cg==