PID_MAX_LIMIT
if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
#define PIDS_MAX (PID_MAX_LIMIT + 1ULL)
static int __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT;
static int pid_max_max = PID_MAX_LIMIT;
BUILD_BUG_ON(PID_MAX_LIMIT >= PIDNS_ADDING);
ns->pid_max = PID_MAX_LIMIT;
#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
BUILD_BUG_ON(MAX_PID < PID_MAX_LIMIT);