2008-08-20 16:50:25

by Oleg Nesterov

Subject: [PATCH, RESEND] posix-timers: simplify de_thread()->exit_itimers() path

(depends on posix-timers-always-do-get_task_structtimer-it_process.patch)

de_thread() postpones release_task(leader) until after exit_itimers().
This was needed because !SIGEV_THREAD_ID timers could use ->group_leader
without get_task_struct(). With the recent changes we can release the
leader earlier and simplify the code.

Signed-off-by: Oleg Nesterov <[email protected]>

--- 26-rc2/fs/exec.c~3_DE_THREAD 2008-08-03 17:16:40.000000000 +0400
+++ 26-rc2/fs/exec.c 2008-08-03 21:35:33.000000000 +0400
@@ -757,7 +757,6 @@ static int de_thread(struct task_struct
struct signal_struct *sig = tsk->signal;
struct sighand_struct *oldsighand = tsk->sighand;
spinlock_t *lock = &oldsighand->siglock;
- struct task_struct *leader = NULL;
int count;

if (thread_group_empty(tsk))
@@ -795,7 +794,7 @@ static int de_thread(struct task_struct
* and to assume its PID:
*/
if (!thread_group_leader(tsk)) {
- leader = tsk->group_leader;
+ struct task_struct *leader = tsk->group_leader;

sig->notify_count = -1; /* for exit_notify() */
for (;;) {
@@ -849,8 +848,9 @@ static int de_thread(struct task_struct

BUG_ON(leader->exit_state != EXIT_ZOMBIE);
leader->exit_state = EXIT_DEAD;
-
write_unlock_irq(&tasklist_lock);
+
+ release_task(leader);
}

sig->group_exit_task = NULL;
@@ -859,8 +859,6 @@ static int de_thread(struct task_struct
no_thread_group:
exit_itimers(sig);
flush_itimer_signals();
- if (leader)
- release_task(leader);

if (atomic_read(&oldsighand->count) != 1) {
struct sighand_struct *newsighand;

2008-08-20 17:51:50

by Roland McGrath

Subject: Re: [PATCH, RESEND] posix-timers: simplify de_thread()->exit_itimers() path

That looks fine to me.

Thanks,
Roland