I see. Thank you very much :-)

At 2018-11-21 16:56:29, "Vladimir Davydov" <vdavydov.dev@gmail.com> wrote:
>On Wed, Nov 21, 2018 at 04:46:48PM +0800, dong wrote:
>> Sorry, I found when I ran `echo 3 >  /proc/sys/vm/drop_caches`, the
>> leak memory was released very slowly. 
>> 
>> The `Page Cache` of the opened log file is the reason to cause leak.
>> Because the `struct page` contains `struct mem_cgroup *mem_cgroup`
>> which has a large chunk of memory. Thanks everyone for helping me to
>> solve the problem.
>
>Ah, so it doesn't seem to be kmem problem at all. The email I sent
>several minutes ago isn't relevant then.
>
>> The last question: If I alloc many small pages and not free them, will
>> I exhaust the memory ( because every page contains `mem_cgroup` )?
>
>Once memory usage is close to the limit, the reclaimer will kick in
>automatically to free those pages and the associated dead cgroups.