| Summary: | cpu.share doesn't limit the cpu usage | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Suqin Huang <shuang> | |
| Component: | kernel | Assignee: | Jacob Tanenbaum <jtanenba> | |
| Status: | CLOSED NOTABUG | QA Contact: | Red Hat Kernel QE team <kernel-qe> | |
| Severity: | medium | Docs Contact: | ||
| Priority: | medium | |||
| Version: | 6.2 | CC: | dhoward, qcai, shuang, sluo | |
| Target Milestone: | rc | Flags: | jtanenba:
needinfo?
(shuang) |
|
| Target Release: | --- | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | Doc Type: | Bug Fix | ||
| Doc Text: | Story Points: | --- | ||
| Clone Of: | ||||
| : | 918395 (view as bug list) | Environment: | ||
| Last Closed: | 2014-03-19 18:00:00 UTC | Type: | --- | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Bug Depends On: | ||||
| Bug Blocks: | 918395 | |||
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 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. It appears that in the absence of additional information cpu.share is acting as it should. Additionally the customer bug attached has been closed |
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: