From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 395C3625FD for ; Mon, 13 Jul 2020 12:21:07 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 2C94219968 for ; Mon, 13 Jul 2020 12:20:37 +0200 (CEST) Received: from mout.web.de (mout.web.de [212.227.17.11]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id 858B91995C for ; Mon, 13 Jul 2020 12:20:35 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1594635629; bh=YOjyamcXIcjG4otiJ2dj33vzHegM5Zn9R7iyDO4dB44=; h=X-UI-Sender-Class:To:From:Subject:Date; b=CQeRgtLxL+B+HcuksaNnmOhn0f7qbAIi51lqs4noKZINl2XJQ04GTs4uhNU9rQmLR +kxfeqXQ+WtV/tBOklAEI0oGqNnJM5xz2VnKDJIKSfksGYkqwACAiJFS8sOT6HNuxf YCEjLw0YG+6HGc96OoUUoHrQ/ARIfqF3gETfXWok= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from Rolands-MacBook-Pro.cybercon.de ([78.34.171.22]) by smtp.web.de (mrweb106 [213.165.67.124]) with ESMTPSA (Nemesis) id 1MQgpA-1kGQNd1vEM-00NkG2 for ; Mon, 13 Jul 2020 12:15:19 +0200 To: PVE User List From: Roland Message-ID: <4900ba10-107e-439c-9716-6e988ae7f5ef@web.de> Date: Mon, 13 Jul 2020 12:15:23 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:vykl3kKbQPYSpuyDSdMDXvg99jCWr2sfCxuDqdxRIz1A4+CbyU5 7+v8kwZYAQTJrdyrvkB3nWqBekzBRdZfteG0e8UN5iDlBPzvwmQ9MzN6tTVyO1oCEMROyb3 2wOLHLpvjAJRMKzOktRT+8qH62miOOX00YjigO0THRlU2fJjVVU7CpSUZsIQUfFcZzDJyK+ KEZiHT/9WIc99iY0+au3Q== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:99ytE0mhc5o=:VijaRkqYSTEbmAKXEGWmG4 FjALSuuh1JLbay1yTJvUhBW/lwTX26LX81WQnMMyWXNMlG0K46ze9U3OtAzGo2EPhuNn0KHFn f+26vbFdqnTZxRbsMu50UsB43dMu8WnCHm709IInah4OZqVgNTtUwuCjwYpXRlUFk/s4Plt0I 9peLjw2TXiVBFuSQ55O0baauCGEp+xdQo6asD4ueEH+ighOCTaViIw/mGZaN/CKd+JH4cGMXW WEajBOUYNla7adW3rwtxP8qhMw0Sn7NLD6Gp1vcrXIBPuB0vLr/ba6epT5eBTyv+UdykuXipZ UWJu8/mwlDaY3JCnoCbKxIVZ1bgp6UJAB9fup234sjJaWqXahVymRgrYC9CRrz3oI7Mg5vzpW 92pQai7xUGFWEctZb9/5CuGEnI1HaYpDXtXoqjVUmQYC4iT5fHToNZZrktcNOUAVMOnON9wmi FKLIXN989G6lit0kuuInGa0cEN3NcdGwa3lGGB1/Ak2G50JYuFiwCnzn5AQ2+jq0hRK0DlTHz mChnrAcVNoCklwV0aC+geOWtaP1Kc6nXgynI52C9DhcDyPyY7utGPBnGJnizVMRVAGC0ZaIo6 pN3v0ywHUPrw0o9ZtH54ONz6W8UEK0HFnkMEz9sHyS8//jNSO3IIou7CGbVdzn6hgR80zTUU3 ajKk9EdmOGcp+rfcTEm6SmCqpq41ljEmeeh+S5I/B05yY7WS9vdu4js/u8OMbOLebgkt4U/Yq dPq48LZjvftdczvCEqRJwgnX9arH/tggoKEZyxLln5EhnWha7jmEmUtCpvLBkNeM2hgA5bKLV lxefeahle1PQPCJ0by6k0RdzJXpaCCWRdnqrV+IMa1IwlrdobhB7AofUPGx2XvodYtfo3Y7QC Qf2mAA5Cz+CDYWcapJcaZvGZJj8YlcQbec8QZleIrBpYZs3xHRdA6xQ7VjzDf/kvKMRzPpe3o 1hFf90FxK223b0f2ed+z9a6uY8D7+LB7+42CT1GgQoaOTQTr5XO9V10z8uMWWy/dA0ZobcTOH /GN2rF8tmo4JrmPhJJdkEyzlsXvuBSBgkk2VuU3uEEGTfk8mvqO4FR8nWIZeKloxPYU6bnKGK G6qJEQHs1N02SMANYrbrDOx9Ip5b/lxVwWFgG+0/+TYbYwZSWSVvdCfQzakHE1rMNkkCYErgB lOyMWOJJMzD97WMd/WN1fwghu9kk4fTefq2Tym8C8CqdZKS/D/Ab49jnJbWCxkFRRCCXldwDZ aQs9A74vQ1QpUGuAt X-SPAM-LEVEL: Spam detection results: 0 DKIM_SIGNED 0.1 Message has a DKIM or DK signature, not necessarily valid DKIM_VALID -0.1 Message has at least one valid DKIM or DK signature DKIM_VALID_AU -0.1 Message has a valid DKIM or DK signature from author's domain DKIM_VALID_EF -0.1 Message has a valid DKIM or DK signature from envelope-from domain FREEMAIL_FROM 0.001 Sender email is commonly abused enduser mail provider RCVD_IN_DNSWL_LOW -0.7 Sender listed at https://www.dnswl.org/, low trust RCVD_IN_MSPIKE_H3 -0.01 Good reputation (+3) RCVD_IN_MSPIKE_WL -0.01 Mailspike good senders SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: [PVE-User] linux idle cpu overhead in kvm - old issue, but still there in 2020... X-BeenThere: pve-user@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE user list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Jul 2020 10:21:07 -0000 hello, i have found that there is an old bug still around in linux, which is causing quite an amount of unnecessary cpu consumption in kvm/proxmox, and thus, wasting precious power. i run some proxmox installations on older systems and on those, it's quite significant difference. on the slowest system, a single debian 10 VM , kvm process is at 20% cpu (VM is 100% idle) when this issue is present. if i change VMs machine type from i440fx(default) to q35 the problem goes away. the same applies when running "powertop --auto-tune" inside the guest (with i440fx type - enable autosuspend for usb-controller + tablet device)= . on some L5630 machine, in proxmox summary i see "CPU usage" drop from 10% to <1%. see: https://bugzilla.redhat.com/show_bug.cgi?id=3D478317 https://bugzilla.redhat.com/show_bug.cgi?id=3D949547 i guess this information could make a difference for people who run a large amount of virtual machines or use older systems/cpu's. on most recent cpu's, i think the difference is not that big. anyway, i really wonder how linux bugs have such great survival capability.... regards roland more references: https://lists.gnu.org/archive/html/qemu-devel/2010-04/msg00149.html https://www.redhat.com/archives/vfio-users/2015-November/msg00159.html