VM costs high CPU by sy 100%

Discussions related to using VirtualBox on Linux hosts.

VM costs high CPU by sy 100%

Postby maybeonly » 26. Sep 2017, 12:37

I have two windows guests on a linux host.
Now each VM costs cpu 100% sy (only one vm is shown, the other is stopped)
I tried to update everything by yum update, but nothing works.

top - 18:28:40 up 37 min,  2 users,  load average: 0.90, 0.89, 0.90
Tasks: 185 total, 1 running, 184 sleeping, 0 stopped, 0 zombie
%Cpu0 : 0.0 us, 99.7 sy, 0.0 ni, 0.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
%Cpu1 : 0.3 us, 0.3 sy, 0.0 ni, 99.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
%Cpu2 : 0.0 us, 0.3 sy, 0.0 ni, 99.7 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
%Cpu3 : 0.3 us, 0.0 sy, 0.0 ni, 99.7 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 16172052 total, 11229400 free, 4626428 used, 316224 buff/cache
KiB Swap: 8193020 total, 8193020 free, 0 used. 11178284 avail Mem

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2892 root 20 0 5876968 4.092g 4.045g S 100.0 26.5 15:40.62 /usr/lib/virtualbox/VBoxHeadless --comment 193 --startvm ******


I've checked its thread by H button in top command, it seems that the main thread (2892) costs the most of cpu
I ran strace on this process and got lots of ioctl as below.

ioctl(7, _IOC(0, 0x56, 0xc1, 0x00), 0)  = 0
ioctl(7, _IOC(0, 0x56, 0xc1, 0x00), 0) = 0
ioctl(7, _IOC(0, 0x56, 0xc1, 0x00), 0) = 0
ioctl(7, _IOC(0, 0x56, 0xc1, 0x00), 0) = 0
ioctl(7, _IOC(0, 0x56, 0xc1, 0x00), 0) = 0
sched_yield() = 0
ioctl(7, _IOC(0, 0x56, 0xc1, 0x00), 0) = 0
ioctl(7, _IOC(0, 0x56, 0xc1, 0x00), 0) = 0
ioctl(7, _IOC(0, 0x56, 0xc1, 0x00), 0) = 0


the guest is Windows server 2016, and the host is
[root@storage ~]# uname -a
Linux storage.*** 3.10.0-693.2.2.el7.x86_64 #1 SMP Tue Sep 12 22:26:13 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
[root@storage ~]# VBoxManage --version
5.1.18r114002


Any idea?
Thank you.

I'm sorry for my poor English.
maybeonly
 
Posts: 2
Joined: 26. Sep 2017, 12:27

Re: VM costs high CPU by sy 100%

Postby mpack » 26. Sep 2017, 13:02

CPU time is not used up by magic: look in the task manager of the guest and find out what process is using CPU or I/O time.
mpack
Site Moderator
 
Posts: 25501
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: VM costs high CPU by sy 100%

Postby maybeonly » 26. Sep 2017, 15:54

mpack wrote:CPU time is not used up by magic: look in the task manager of the guest and find out what process is using CPU or I/O time.

The task manager on windows show nothing but I installed a clean Windows and it works fine now.
Thank you.
maybeonly
 
Posts: 2
Joined: 26. Sep 2017, 12:27


Return to VirtualBox on Linux Hosts

Who is online

Users browsing this forum: No registered users and 16 guests