挂载cgroup后创建了一些subgroup,再次挂载cgroup出现EBUSY问题。
mount -t cgroup -o cpuset,debug cgroup /cgroup
master# mount -t cgroup -o cpuset,debug cgroup /cgroup ---挂载cgroup
master# cd /cgroup
master# mkdir -p ltp t2 ---在cgroup下,创建了2个subgroup
master# ls
cgroup.clone_children cpuset.memory_pressure debug.current_css_set_refcount
cgroup.procs cpuset.memory_pressure_enabled debug.releasable
cgroup.sane_behavior cpuset.memory_spread_page debug.taskcount
cpuset.cpu_exclusive cpuset.memory_spread_slab ltp
cpuset.cpus cpuset.mems notify_on_release
cpuset.effective_cpus cpuset.sched_load_balance release_agent
cpuset.effective_mems cpuset.sched_relax_domain_level t2
cpuset.mem_exclusive debug.cgroup_css_links tasks
cpuset.mem_hardwall debug.current_css_set
cpuset.memory_migrate debug.current_css_set_cg_links
master#
master# umount /cgroup ---卸载cgroup
master#
master# mount -t cgroup -o debug cgroup /cgroup
mount: mounting cgroup on /cgroup failed: Device or resource busy
master# mount -t cgroup -o cpuset cgroup /cgroup
mount: mounting cgroup on /cgroup failed: Device or resource busy
---当cgroup下创建了subgroup时,可以用umount完成卸载。但如果再次挂载可能会失败(使用不同的-o选项)。报Device or resource busy。这是因为卸载cgroup时没有删除里面创建的subgroup。我们可以使用相同的-o选项,再一次挂载cgroup。
master# mount -t cgroup -o cpuset,debug cgroup /cgroup
挂载上后,通过ls /cgroup命令,我们可以看到之前创建的subgroup还在,所以先将subgroup删掉,rmdir ltp t2。在去挂载就可以了。
master# rmdir ltp t2
master# ls
cgroup.clone_children cpuset.memory_migrate debug.current_css_set
cgroup.procs cpuset.memory_pressure debug.current_css_set_cg_links
cgroup.sane_behavior cpuset.memory_pressure_enabled debug.current_css_set_refcount
cpuset.cpu_exclusive cpuset.memory_spread_page debug.releasable
cpuset.cpus cpuset.memory_spread_slab debug.taskcount
cpuset.effective_cpus cpuset.mems notify_on_release
cpuset.effective_mems cpuset.sched_load_balance release_agent
cpuset.mem_exclusive cpuset.sched_relax_domain_level tasks
cpuset.mem_hardwall debug.cgroup_css_links
master# umount /cgroup
master# mount -t cgroup -o debug cgroup /cgroup
master# ls /cgroup/
cgroup.clone_children debug.cgroup_css_links debug.current_css_set_refcount notify_on_release
cgroup.procs debug.current_css_set debug.releasable release_agent
cgroup.sane_behavior debug.current_css_set_cg_links debug.taskcount tasks
master#