posix-timers: Cleanup reaped target handling

When a timer's target is seen to be buried, for example on calls
to timer_gettime(), the posix cpu timers code behaves a bit
like a garbage collector and releases early the reference to the
task.

Then again, this optimization complicates the code for no much
value: it's up to the user to release the timer and its associated
ressources by calling timer_delete() after it buries the target
tasks.

Remove this to simplify the code.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index c5d1ef5..dc4355b 100644 (file)
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -639,8 +639,6 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int flags,
         */
        if (unlikely(p->sighand == NULL)) {
                read_unlock(&tasklist_lock);
-               put_task_struct(p);
-               timer->it.cpu.task = NULL;
                return -ESRCH;
        }
 
@@ -808,8 +806,6 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
                         * We can't even collect a sample any more.
                         * Call the timer disarmed, nothing else to do.
                         */
-                       put_task_struct(p);
-                       timer->it.cpu.task = NULL;
                        timer->it.cpu.expires = 0;
                        read_unlock(&tasklist_lock);
                        goto dead;
@@ -1059,8 +1055,6 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
                         * The process has been reaped.
                         * We can't even collect a sample any more.
                         */
-                       put_task_struct(p);
-                       timer->it.cpu.task = p = NULL;
                        timer->it.cpu.expires = 0;
                        read_unlock(&tasklist_lock);
                        goto out;