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Description of problem:
Version-Release number of selected component (if applicable):
How reproducible:
100%
Steps to Reproduce:
1. create cgroups
# mount -t cgroup -o cpu none /cgroup
# mkdir /cgroup/cpu1
# mkdir /cgroup/cpu2
2. set cpu.share for each cgroup
# ech0 1024 > /cgroup/cpu1/cpu.share
# echo 2048 > /cgroup/cpu2/cpu.share
3. boot two guests (both with 2 vcpu)
4. echo pidof-guest1 to > /cgroup/cpu1/tasks (contain threads)
5. echo pidof-guest2 to > /cgroup/cpu2/tasks (contain threads)
6. run the following script in guests:
#include <stdio.h>
int main(void){
int i;
for(;;){
i += 1;
}
return 0;
}
guest1: run 3 tasks with above script
guest2: run 1 tasks with above script
Actual results:
cpu usage: guest1 vs. guest2 : 300% vs. 100%
Expected results:
cpu usage: guest1 vs. guest2 : 50% vs. 100%
Additional info:
Hi all,
I tried the kernel-2.6.32-356.el6.x86_64, but still hit this issue, the cpu.shares fail to limit the cpu usage correctly. btw, i also hit it in rhel7 host, i will clone it to rhel7.
host info:
kernel-2.6.32-356.el6.x86_64
qemu-kvm-0.12.1.2-2.358.el6.x86_64
guest info:
kernel-2.6.32-356.el6.x86_64
Steps:
the same to comment #0.
# echo 1024 > /cgroup/cpu1/cpu.shares
# echo 2048 > /cgroup/cpu2/cpu.shares
both two guests with 2 vcpu.
Results:
The cpu usage: guest1 vs. guest2 : 200% vs. 100%
# top
...
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
13865 root 20 0 2586m 602m 4540 S 199.4 7.7 4:06.69 qemu-kvm <--guest1
13888 root 20 0 2559m 603m 4540 S 99.4 7.7 3:09.15 qemu-kvm <--guest2
If run 2 tasks with above script in each guest, the cpu usage: guest1 vs. guest2 : 200% vs. 200%
# top
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
13865 root 20 0 2586m 602m 4540 S 199.7 7.7 1:57.07 qemu-kvm <--guest1
13888 root 20 0 2559m 602m 4540 S 199.7 7.7 1:41.49 qemu-kvm <--guest2
Best Regards.
sluo
Comment 7RHEL Program Management
2013-10-14 05:15:35 UTC
This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.
Description of problem: Version-Release number of selected component (if applicable): How reproducible: 100% Steps to Reproduce: 1. create cgroups # mount -t cgroup -o cpu none /cgroup # mkdir /cgroup/cpu1 # mkdir /cgroup/cpu2 2. set cpu.share for each cgroup # ech0 1024 > /cgroup/cpu1/cpu.share # echo 2048 > /cgroup/cpu2/cpu.share 3. boot two guests (both with 2 vcpu) 4. echo pidof-guest1 to > /cgroup/cpu1/tasks (contain threads) 5. echo pidof-guest2 to > /cgroup/cpu2/tasks (contain threads) 6. run the following script in guests: #include <stdio.h> int main(void){ int i; for(;;){ i += 1; } return 0; } guest1: run 3 tasks with above script guest2: run 1 tasks with above script Actual results: cpu usage: guest1 vs. guest2 : 300% vs. 100% Expected results: cpu usage: guest1 vs. guest2 : 50% vs. 100% Additional info: