[patch V2 1/5] posix-cpu-timers: Split run_posix_cpu_timers()

Thomas Gleixner
2020-07-16T20:22:15Z

Split it up as a preparatory step to move the heavy lifting out of
interrupt context.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/time/posix-cpu-timers.c | 38 ++++++++++++++++++++++----------------
1 file changed, 22 insertions(+), 16 deletions(-)

--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -1080,27 +1080,12 @@ static inline bool fastpath_timer_check(
return false;
}

-/*
- * This is called from the timer interrupt handler. The irq handler has
- * already updated our counts. We need to check if any timers fire now.
- * Interrupts are disabled.
- */
-void run_posix_cpu_timers(void)
+static void __run_posix_cpu_timers(struct task_struct *tsk)
{
- struct task_struct *tsk = current;
struct k_itimer *timer, *next;
unsigned long flags;
LIST_HEAD(firing);

- lockdep_assert_irqs_disabled();
-
- /*
- * The fast path checks that there are no expired thread or thread
- * group timers. If that's so, just return.
- */
- if (!fastpath_timer_check(tsk))
- return;
-
lockdep_posixtimer_enter();
if (!lock_task_sighand(tsk, &flags)) {
lockdep_posixtimer_exit();
@@ -1151,6 +1136,27 @@ void run_posix_cpu_timers(void)
}

/*
+ * This is called from the timer interrupt handler. The irq handler has
+ * already updated our counts. We need to check if any timers fire now.
+ * Interrupts are disabled.
+ */
+void run_posix_cpu_timers(void)
+{
+ struct task_struct *tsk = current;
+
+ lockdep_assert_irqs_disabled();
+
+ /*
+ * The fast path checks that there are no expired thread or thread
+ * group timers. If that's so, just return.
+ */
+ if (!fastpath_timer_check(tsk))
+ return;
+
+ __run_posix_cpu_timers(tsk);
+}
+
+/*
* Set one of the process-wide special case CPU timers or RLIMIT_CPU.
* The tsk->sighand->siglock must be held by the caller.
*/