Received: by 2002:a25:f815:0:0:0:0:0 with SMTP id u21csp4122157ybd; Tue, 25 Jun 2019 14:37:24 -0700 (PDT) X-Google-Smtp-Source: APXvYqyCq/cqkmyjg6FDeHmy0qaUIp5G3i+BAj0WPVwV39mV9oOUjyBzulIU5vHvS4hWX/Uief86 X-Received: by 2002:a63:4d50:: with SMTP id n16mr41380175pgl.146.1561498644022; Tue, 25 Jun 2019 14:37:24 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1561498644; cv=none; d=google.com; s=arc-20160816; b=a2whluh+q7rjrv9cG+YcIMKnPmIC+/VQJOYNMfBlJRQLlJmAvDMaLoFMpFeWJ1pwoL qYjYUf9n5nVjWj03wv6vYt2teWFYgNiZuN5I0TcBDijiTy8l5M5KJhpm8JSTR48W4ngO sKFZQbDXG+AYonJFYp+sDAGEzdsLutYGcDTaBjAesgba3CBY8D2t+IMBrCv96SK23mqX W/rCIYLSpUFCpnxk0mcMta3Z69Bh+gPNhsc/YCPbibGm35bBJWr8meMlLQUX61ZtvrJB shQLjys1BUqu0XrABRm+/4QdB+aUyZmOULfthyhMjG++BiymGLKpe8l70XoMSdA9bzT/ b9hg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:autocrypt:openpgp:from:references:cc:to:subject; bh=/pNR33hInwOcUcUGEtG0BGh6SkYrrjh+q1CfT90Yuck=; b=CRsUr3sOpQnIvwGC6ryhNTzZ1zJGr/wlGejyVNpAwsAbr2Boc+JrGuLIO1gShBsCU7 Av1e1XOJwy2cF3g1oh+4AqwD/IXBsp0Ekca3KQvYfERTiO/QWnatAYBB4LycbJCy+94M WeeYBhFtSdvIoVnTytDHHPlCAmUAvKPYA8/i5FS7ssO8xGB7ACYmnBiXUaVmIdBdgker P/MSHGfMpnDW5QCCcEMPNU+GPycJgtgVx+dMhFeMOOQu8w7opqYPEEtAT3yhV7+BLAOV 4UCMQDzmIuSzFqPzzleMV8Q0NulQs30RVQ1eA/GOIL9zS7tXJDsWoPeyPCPwsTECltpP hjXw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id j17si14652783pfr.13.2019.06.25.14.37.07; Tue, 25 Jun 2019 14:37:24 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726410AbfFYVgp (ORCPT + 99 others); Tue, 25 Jun 2019 17:36:45 -0400 Received: from mga17.intel.com ([192.55.52.151]:49977 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725914AbfFYVgp (ORCPT ); Tue, 25 Jun 2019 17:36:45 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jun 2019 14:36:45 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,417,1557212400"; d="scan'208";a="172503859" Received: from ray.jf.intel.com (HELO [10.7.201.139]) ([10.7.201.139]) by orsmga002.jf.intel.com with ESMTP; 25 Jun 2019 14:36:44 -0700 Subject: Re: [PATCH 5/9] x86/mm/tlb: Optimize local TLB flushes To: Nadav Amit , Peter Zijlstra , Andy Lutomirski Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Borislav Petkov , x86@kernel.org, Thomas Gleixner , Dave Hansen References: <20190613064813.8102-1-namit@vmware.com> <20190613064813.8102-6-namit@vmware.com> From: Dave Hansen Openpgp: preference=signencrypt Autocrypt: addr=dave.hansen@intel.com; keydata= mQINBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC 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/aCccJK18ZwNjFhqr4MliQARAQABtEVEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gKEludGVsIFdvcmsgQWRkcmVzcykgPGRhdmUuaGFuc2VuQGludGVs LmNvbT6JAjgEEwECACIFAlQ+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 5TsyLYdPur3TXm7XDBdmmyQVJjnJKYK9AQxj95KlXLVO38lcuQINBFRjzmoBEACyAxbvUEhd 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+ZkptgGjikQARAQABiQIfBBgBAgAJBQJUY85qAhsMAAoJEGg1lTBwyZKw 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 Message-ID: <86e04985-7884-3d33-c479-92614b4e4342@intel.com> Date: Tue, 25 Jun 2019 14:36:44 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1 MIME-Version: 1.0 In-Reply-To: <20190613064813.8102-6-namit@vmware.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/12/19 11:48 PM, Nadav Amit wrote: > While the updated smp infrastructure is capable of running a function on > a single local core, it is not optimized for this case. OK, so flush_tlb_multi() is optimized for flushing local+remote at the same time and is also (near?) the most optimal way to flush remote-only. But, it's not as optimized at doing local-only flushes. But, flush_tlb_on_cpus() *is* optimized for local-only flushes. Right? Can we distill that down to any particular advise that we can comment these suckers with? For instance, flush_tlb_multi() is apparently not safe to call ever by itself without a 'flush_tlb_multi_enabled' check first. It's also, suboptimal for local flushes apparently.