From: Sukadev Bhattiprolu Use task_pgrp() and task_session() in copy_process(), and avoid find_pid() call when attaching the task to its process group and session. Signed-off-by: Sukadev Bhattiprolu Cc: Cedric Le Goater Cc: Dave Hansen Cc: Serge Hallyn Cc: Acked-by: Eric W. Biederman Signed-off-by: Andrew Morton --- kernel/fork.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff -puN kernel/fork.c~use-task_pgrp-task_session-in-copy_process kernel/fork.c --- a/kernel/fork.c~use-task_pgrp-task_session-in-copy_process +++ a/kernel/fork.c @@ -1247,14 +1247,11 @@ static struct task_struct *copy_process( __ptrace_link(p, current->parent); if (thread_group_leader(p)) { - pid_t pgid = process_group(current); - pid_t sid = process_session(current); - p->signal->tty = current->signal->tty; - p->signal->pgrp = pgid; + p->signal->pgrp = process_group(current); set_signal_session(p->signal, process_session(current)); - attach_pid(p, PIDTYPE_PGID, find_pid(pgid)); - attach_pid(p, PIDTYPE_SID, find_pid(sid)); + attach_pid(p, PIDTYPE_PGID, task_pgrp(current)); + attach_pid(p, PIDTYPE_SID, task_session(current)); list_add_tail_rcu(&p->tasks, &init_task.tasks); __get_cpu_var(process_counts)++; _