hello，linux boss I found a problem in the process of using linux memcg，When I turned swap off, the memcg memory I created with the following script could not be deleted with echo 0 > memory.force_empty, as explained below。 ---------------------------------------------------------------------------------------------------------- step1：swapoff -a step2：use this script to create memcg #!/bin/bash mkdir -p /tmp/test for i in 'seq 2000' do sudo mkdir -p /sys/fs/cgroup/memory/user.slice/user-0.slice/test$ {i} sudo echo $$ > /sys/fs/cgroup/memory/user.slice/user-0.slice/test$ {i}/tasks sudo echo 'data' > /tmp/test/test$ {i} sudo echo $$ > /sys/fs/cgroup/memory/user.slice/user-0.slice/tasks sudo rmdir /sys/fs/cgroup/memory/user.slice/user-0.slice/test$ {i} done step3：view /proc/cgroup and /proc/meminfo files [root@localhost ~]# cat /proc/cgroups #subsys_name hierarchy num_cgroups enabled cpuset 10 1 1 cpu 4 1 1 cpuacct 4 1 1 blkio 13 1 1 memory 14 2009 1 devices 6 94 1 [root@localhost ~]# cat /proc/meminfo | grep Percpu Percpu: 600576 kB step4：when I use "echo 0 > /sys/fs/cgroup/memory/user.slice/user-0.slice/memory.force_empty", I find the num_cgroups of memory and percpu have no changed [root@localhost ~]# echo 0 > /sys/fs/cgroup/memory/user.slice/user-0.slice/memory.force_empty [root@localhost ~]# cat /proc/cgroups #subsys_name hierarchy num_cgroups enabled cpuset 10 1 1 cpu 4 1 1 cpuacct 4 1 1 blkio 13 1 1 memory 14 2039 1 devices 6 87 1 [root@localhost ~]# cat /proc/meminfo | grep Percpu Percpu: 600576 kB step 5: when I use swapon -a to open swap, then echo 0 > /sys/fs/cgroup/memory/user.slice/user-0.slice/memory.force_empty again [root@localhost ~]# swapon -a [root@localhost ~]# echo 0 > /sys/fs/cgroup/memory/user.slice/user-0.slice/memory.force_empty step 6: view /proc/cgroup and /proc/meminfo files ,I found the the num_cgroups of memory and percpu have been reduced. [root@localhost ~]# cat /proc/cgroups #subsys_name hierarchy num_cgroups enabled cpuset 10 1 1 cpu 4 1 1 cpuacct 4 1 1 blkio 13 1 1 memory 14 185 1 devices 6 87 1 freezer 9 1 1 [root@localhost ~]# cat /proc/meminfo | grep Percpu Percpu: 120832 kB -------------------------------------------------------------------------------------------------------- Therefore, I want to know why swap affects memcg memory reclamation, echo 0 > memory.force_empty this interface should force the memory used by the cgroup to be reclaimed. I want to know why ,I look forward to hearing back from the community. Thanks. ----------------------------------------- 刘婧 计算产品部 手机：18896725597 邮箱：liujing@xxxxxxxxxxxxxxxxxxxx 中移（苏州）软件技术有限公司 |
----------------------------------------- 刘婧 计算产品部 手机：18896725597 邮箱：liujing@xxxxxxxxxxxxxxxxxxxx 中移（苏州）软件技术有限公司 |
