Comment 14 for bug 1392176

The patch does not work for us.
We tried out the below test:

 root@ubuntu1504:~# cat /etc/issue
 Ubuntu Vivid Vervet (development branch) \n \l
 root@ubuntu1504:~# cgmanager --version
 cgmanager 0.36
 root@ubuntu1504:~# uname -a
 Linux ubuntu1504 3.18.0-13-generic #14-Ubuntu SMP Fri Feb 6 09:57:41 UTC 2015 ppc64le ppc64le ppc64le GNU/Linux
 root@ubuntu1504:~#
 root@ubuntu1504:/sys/devices/system/cpu# ps aux | grep bash
 root 955 0.2 0.3 8576 7104 hvc0 S 01:52 0:00 -bash
 root 1001 0.0 0.1 4992 3072 hvc0 S+ 01:53 0:00 grep --color=auto bash
 root@ubuntu1504:/sys/devices/system/cpu# taskset -p 955
 pid 955's current affinity mask: ffff
 root@ubuntu1504:/sys/devices/system/cpu# echo 0 > cpu15/online
 root@ubuntu1504:/sys/devices/system/cpu# taskset -p 955
 pid 955's current affinity mask: 7fff
 root@ubuntu1504:/sys/devices/system/cpu# echo 1 > cpu15/online
 root@ubuntu1504:/sys/devices/system/cpu# taskset -p 955
 pid 955's current affinity mask: 7fff

You can see that the cpumask of the task does not have the cpu that we got back online
and we are using the version of cgmanager that has the fix in.

Can you explain what the patch does ? This will help us figure out why its not working.
On another note, to make things clearer, there are two requirements to take care of:

a. When a cpu goes offline and comes back online, the cpuset of tasks must get updated both times to reflect the online mask
b. When a cpu in the possible_mask is brought online anytime after bootup, that too should get updated in the cpuset of the tasks.

Regards
Preeti U Murthy