From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Chmielewski Subject: Re: strange guest slowness after some time Date: Mon, 09 Mar 2009 11:22:01 +0100 Message-ID: <49B4EDC9.9020504@wpkg.org> References: <49B29705.6000904@wpkg.org> <49B4E7A6.3090601@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: "kvm@vger.kernel.org" To: Avi Kivity Return-path: Received: from mx03.syneticon.net ([78.111.66.105]:59635 "EHLO mx03.syneticon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752862AbZCIKWI (ORCPT ); Mon, 9 Mar 2009 06:22:08 -0400 In-Reply-To: <49B4E7A6.3090601@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity schrieb: > I'm guessing there's a problem with timers or timer interrupts. > > What is the host cpu? 4 entries like this in /proc/cpuinfo: processor : 3 vendor_id : AuthenticAMD cpu family : 15 model : 65 model name : Dual-Core AMD Opteron(tm) Processor 2212 stepping : 2 cpu MHz : 2000.000 cache size : 1024 KB physical id : 1 siblings : 2 core id : 1 cpu cores : 2 fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm3dnowext 3dnow rep_good pni cx16 lahf_lm cmp_legacy svm extapic cr8_legacy bogomips : 3993.03 TLB size : 1024 4K pages clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: ts fid vid ttp tm stc > Does the problem occur if you pin a guest to a cpu with taskset? Like this? # taskset -p 01 22906 (doesn't help) # taskset -p 02 22906 (doesn't help) But if I do: # taskset -p 03 22906 or # taskset -p 04 22906 it fixes it _rarely_ for the first few seconds, then it's broken again, until I switch the CPUs again (look at ping 9 and 10; other pings are also slow, unaffected guests are around 1 ms): # ping -c 10 192.168.113.85 PING 192.168.113.85 (192.168.113.85) 56(84) bytes of data. 64 bytes from 192.168.113.85: icmp_seq=1 ttl=64 time=22.0 ms 64 bytes from 192.168.113.85: icmp_seq=2 ttl=64 time=23.7 ms 64 bytes from 192.168.113.85: icmp_seq=3 ttl=64 time=2.96 ms 64 bytes from 192.168.113.85: icmp_seq=4 ttl=64 time=51.3 ms 64 bytes from 192.168.113.85: icmp_seq=5 ttl=64 time=22.2 ms 64 bytes from 192.168.113.85: icmp_seq=6 ttl=64 time=1.60 ms 64 bytes from 192.168.113.85: icmp_seq=7 ttl=64 time=49.8 ms 64 bytes from 192.168.113.85: icmp_seq=8 ttl=64 time=23.3 ms 64 bytes from 192.168.113.85: icmp_seq=9 ttl=64 time=999 ms 64 bytes from 192.168.113.85: icmp_seq=10 ttl=64 time=822 ms -- Tomasz Chmielewski http://wpkg.org