From e713d0dab21a68500720e222fa02567fc7dfb14b Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Thu, 10 May 2007 22:22:58 -0700 Subject: attach_pid() with struct pid parameter attach_pid() currently takes a pid_t and then uses find_pid() to find the corresponding struct pid. Sometimes we already have the struct pid. We can then skip find_pid() if attach_pid() were to take a struct pid parameter. Signed-off-by: Sukadev Bhattiprolu Cc: Cedric Le Goater Cc: Dave Hansen Cc: Serge Hallyn Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 4 ++-- kernel/fork.c | 11 +++++++---- kernel/pid.c | 9 ++++++--- kernel/sys.c | 2 +- 4 files changed, 16 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 7a5fd77f8fb..e93691e9b32 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -302,12 +302,12 @@ void __set_special_pids(pid_t session, pid_t pgrp) if (process_session(curr) != session) { detach_pid(curr, PIDTYPE_SID); set_signal_session(curr->signal, session); - attach_pid(curr, PIDTYPE_SID, session); + attach_pid(curr, PIDTYPE_SID, find_pid(session)); } if (process_group(curr) != pgrp) { detach_pid(curr, PIDTYPE_PGID); curr->signal->pgrp = pgrp; - attach_pid(curr, PIDTYPE_PGID, pgrp); + attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp)); } } diff --git a/kernel/fork.c b/kernel/fork.c index da92e01aba6..6031800c94c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1249,16 +1249,19 @@ static struct task_struct *copy_process(unsigned long clone_flags, __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 = process_group(current); + p->signal->pgrp = pgid; set_signal_session(p->signal, process_session(current)); - attach_pid(p, PIDTYPE_PGID, process_group(p)); - attach_pid(p, PIDTYPE_SID, process_session(p)); + attach_pid(p, PIDTYPE_PGID, find_pid(pgid)); + attach_pid(p, PIDTYPE_SID, find_pid(sid)); list_add_tail_rcu(&p->tasks, &init_task.tasks); __get_cpu_var(process_counts)++; } - attach_pid(p, PIDTYPE_PID, p->pid); + attach_pid(p, PIDTYPE_PID, find_pid(p->pid)); nr_threads++; } diff --git a/kernel/pid.c b/kernel/pid.c index d3ad724afa8..d76f59326bd 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -247,13 +247,16 @@ struct pid * fastcall find_pid(int nr) } EXPORT_SYMBOL_GPL(find_pid); -int fastcall attach_pid(struct task_struct *task, enum pid_type type, int nr) +/* + * attach_pid() must be called with the tasklist_lock write-held. + */ +int fastcall attach_pid(struct task_struct *task, enum pid_type type, + struct pid *pid) { struct pid_link *link; - struct pid *pid; link = &task->pids[type]; - link->pid = pid = find_pid(nr); + link->pid = pid; hlist_add_head_rcu(&link->node, &pid->tasks[type]); return 0; diff --git a/kernel/sys.c b/kernel/sys.c index df4c3a8f5df..872271ccc38 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1488,7 +1488,7 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) if (process_group(p) != pgid) { detach_pid(p, PIDTYPE_PGID); p->signal->pgrp = pgid; - attach_pid(p, PIDTYPE_PGID, pgid); + attach_pid(p, PIDTYPE_PGID, find_pid(pgid)); } err = 0; -- cgit v1.2.3