From aafe6c2a2b6bce5a3a4913ce5c07e85ea143144d Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 27 Sep 2006 01:51:13 -0700 Subject: [PATCH] [PATCH] de_thread: Use tsk not current Ingo Oeser pointed out that because current expands to an inline function it is more space efficient and somewhat faster to simply keep a cached copy of current in another variable. This patch implements that for the de_thread function. (akpm: saves nearly 100 bytes of text on x86) Signed-off-by: Eric W. Biederman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/exec.c | 46 +++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 23 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index b7aa3d6422..97df6e0aea 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -595,7 +595,7 @@ static int de_thread(struct task_struct *tsk) if (!newsighand) return -ENOMEM; - if (thread_group_empty(current)) + if (thread_group_empty(tsk)) goto no_thread_group; /* @@ -620,17 +620,17 @@ static int de_thread(struct task_struct *tsk) * Reparenting needs write_lock on tasklist_lock, * so it is safe to do it under read_lock. */ - if (unlikely(current->group_leader == child_reaper)) - child_reaper = current; + if (unlikely(tsk->group_leader == child_reaper)) + child_reaper = tsk; - zap_other_threads(current); + zap_other_threads(tsk); read_unlock(&tasklist_lock); /* * Account for the thread group leader hanging around: */ count = 1; - if (!thread_group_leader(current)) { + if (!thread_group_leader(tsk)) { count = 2; /* * The SIGALRM timer survives the exec, but needs to point @@ -639,14 +639,14 @@ static int de_thread(struct task_struct *tsk) * synchronize with any firing (by calling del_timer_sync) * before we can safely let the old group leader die. */ - sig->tsk = current; + sig->tsk = tsk; spin_unlock_irq(lock); if (hrtimer_cancel(&sig->real_timer)) hrtimer_restart(&sig->real_timer); spin_lock_irq(lock); } while (atomic_read(&sig->count) > count) { - sig->group_exit_task = current; + sig->group_exit_task = tsk; sig->notify_count = count; __set_current_state(TASK_UNINTERRUPTIBLE); spin_unlock_irq(lock); @@ -662,13 +662,13 @@ static int de_thread(struct task_struct *tsk) * do is to wait for the thread group leader to become inactive, * and to assume its PID: */ - if (!thread_group_leader(current)) { + if (!thread_group_leader(tsk)) { /* * Wait for the thread group leader to be a zombie. * It should already be zombie at this point, most * of the time. */ - leader = current->group_leader; + leader = tsk->group_leader; while (leader->exit_state != EXIT_ZOMBIE) yield(); @@ -682,12 +682,12 @@ static int de_thread(struct task_struct *tsk) * When we take on its identity by switching to its PID, we * also take its birthdate (always earlier than our own). */ - current->start_time = leader->start_time; + tsk->start_time = leader->start_time; write_lock_irq(&tasklist_lock); - BUG_ON(leader->tgid != current->tgid); - BUG_ON(current->pid == current->tgid); + BUG_ON(leader->tgid != tsk->tgid); + BUG_ON(tsk->pid == tsk->tgid); /* * An exec() starts a new thread group with the * TGID of the previous thread group. Rehash the @@ -700,17 +700,17 @@ static int de_thread(struct task_struct *tsk) * Note: The old leader also uses this pid until release_task * is called. Odd but simple and correct. */ - detach_pid(current, PIDTYPE_PID); - current->pid = leader->pid; - attach_pid(current, PIDTYPE_PID, current->pid); - transfer_pid(leader, current, PIDTYPE_PGID); - transfer_pid(leader, current, PIDTYPE_SID); - list_replace_rcu(&leader->tasks, ¤t->tasks); + detach_pid(tsk, PIDTYPE_PID); + tsk->pid = leader->pid; + attach_pid(tsk, PIDTYPE_PID, tsk->pid); + transfer_pid(leader, tsk, PIDTYPE_PGID); + transfer_pid(leader, tsk, PIDTYPE_SID); + list_replace_rcu(&leader->tasks, &tsk->tasks); - current->group_leader = current; - leader->group_leader = current; + tsk->group_leader = tsk; + leader->group_leader = tsk; - current->exit_signal = SIGCHLD; + tsk->exit_signal = SIGCHLD; BUG_ON(leader->exit_state != EXIT_ZOMBIE); leader->exit_state = EXIT_DEAD; @@ -750,7 +750,7 @@ no_thread_group: spin_lock(&oldsighand->siglock); spin_lock_nested(&newsighand->siglock, SINGLE_DEPTH_NESTING); - rcu_assign_pointer(current->sighand, newsighand); + rcu_assign_pointer(tsk->sighand, newsighand); recalc_sigpending(); spin_unlock(&newsighand->siglock); @@ -761,7 +761,7 @@ no_thread_group: kmem_cache_free(sighand_cachep, oldsighand); } - BUG_ON(!thread_group_leader(current)); + BUG_ON(!thread_group_leader(tsk)); return 0; } -- 2.39.5