On Tue, Mar 7, 2017 at 3:04 PM, Oleg Nesterov <[email protected]> wrote: > On 03/06, Peter Zijlstra wrote: >> >> and this is a failed fork(). >> >> >> However, inherited events don't have a filedesc to fput(), and >> similarly, a task that fails for has never been visible to attach a perf >> event to because it never hits the pid-hash. > > Yes, it is not visible to find_task_by_vpid() until copy_process() does > attach_pid(PIDTYPE_PID), and copy_process() can't fail after that.
I would what is that that is failed in copy_process. Could it be perf_event_init_task itself? Maybe it leaves a pointer to p in some shared state on some error conditions?
