On 07/05, Xishi Qiu wrote:
>
> I find pid_namespace leak by "cat /proc/slabinfo | grep pid_namespace".
> The kernel version is RHEL 7.1 (kernel v3.10 stable).
> The following is the test case, after several times, the count of
> pid_namespace
> become very large, is it correct?
Apparently not,
> I also test mainline, and the count will increase too, but it seems stably
> later.
And I can't reproduce the problem with the latest rhel7 kernel.
And just in case, I have no idea what actually slub reports as "active_objs" but
certainly this is not the number of allocated "in use" objects, so it is fine if
this counter doesn't go to zero when your test-case exits. But it should not
grow
"too much".
> BTW, this patch doesn't help.
> 24c037ebf5723d4d9ab0996433cee4f96c292a4d
> exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting
Sure, it can't help, your test-case doesn't fork other processes which could
race
with the exiting sub-namespace init.
> int main()
> {
> pid_t pid, child_pid;
> int i, status;
> void *stack;
>
> for (i = 0; i < 100; i++) {
> stack = malloc(8192);
> pid = clone(&test, (char *)stack + 8192,
> CLONE_NEWPID|SIGCHLD, 0);
> }
>
> sleep(5);
is this sleep() really needed to trigger the problem?
Oleg.
