On 04/27, Eric W. Biederman wrote: > > Oleg Nesterov <oleg@xxxxxxxxxx> writes: > > > Eric, > > > > I am sick today and can't read the code, but I feel this patch is not > > right ... please correct me. > > > > So, iiuc when posix_cpu_timer_create() is called and CPUCLOCK_PERTHREAD > > is false we roughly have > > > > task = pid_task(pid, PIDTYPE_TGID); // lookup_task() > > > > /* WINDOW */ > > > > timer->it.cpu.pid = = get_task_pid(task, PIDTYPE_TGID) // posix_cpu_timer_create() > > > > Now suppose that we race with mt-exec and this "task" is the old leader; > > it can be release_task()'ed in the WINDOW above and then get_task_pid() > > will return NULL. > > Except it is asking for PIDTYPE_TGID. > > task->signal Ah yes, I knew I missed something... Oleg.
