Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner: "The time/timekeeping/timer folks deliver with this update: - Fix a reintroduced signed/unsigned issue and cleanup the whole signed/unsigned mess in the timekeeping core so this wont happen accidentaly again. - Add a new trace clock based on boot time - Prevent injection of random sleep times when PM tracing abuses the RTC for storage - Make posix timers configurable for real tiny systems - Add tracepoints for the alarm timer subsystem so timer based suspend wakeups can be instrumented - The usual pile of fixes and updates to core and drivers" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) timekeeping: Use mul_u64_u32_shr() instead of open coding it timekeeping: Get rid of pointless typecasts timekeeping: Make the conversion call chain consistently unsigned timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion alarmtimer: Add tracepoints for alarm timers trace: Update documentation for mono, mono_raw and boot clock trace: Add an option for boot clock as trace clock timekeeping: Add a fast and NMI safe boot clock timekeeping/clocksource_cyc2ns: Document intended range limitation timekeeping: Ignore the bogus sleep time if pm_trace is enabled selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous" clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map() arm64: dts: rockchip: Arch counter doesn't tick in system suspend clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend posix-timers: Make them configurable posix_cpu_timers: Move the add_device_randomness() call to a proper place timer: Move sys_alarm from timer.c to itimer.c ptp_clock: Allow for it to be optional Kconfig: Regenerate *.c_shipped files after previous changes ...

Linus Torvalds committed 9 years ago

Commit 9465d9c2 parents e71c397 c029a2b61 files · +1479 −1041Browse files

Showing the changes to kernel/time/timer.c (1 of 61 files). Show all

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kernel/time/timer.c+18−30

 		irq_work_tick();
 #endif
 	scheduler_tick();
-	run_posix_cpu_timers(p);
+	if (IS_ENABLED(CONFIG_POSIX_TIMERS))
+		run_posix_cpu_timers(p);
 }
 /**
 	raise_softirq(TIMER_SOFTIRQ);
 }
-#ifdef __ARCH_WANT_SYS_ALARM
-/*
- * For backwards compatibility?  This can be done in libc so Alpha
- * and all newer ports shouldn't need it.
- */
-SYSCALL_DEFINE1(alarm, unsigned int, seconds)
-{
-	return alarm_setitimer(seconds);
-}
-#endif
 static void process_timeout(unsigned long __data)
 {
 	wake_up_process((struct task_struct *)__data);
  * You can set the task state as follows -
  *
  * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
- * pass before the routine returns. The routine will return 0
+ * pass before the routine returns unless the current task is explicitly
+ * woken up, (e.g. by wake_up_process())".
  *
  * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
- * delivered to the current task. In this case the remaining time
+ * delivered to the current task or the current task is explicitly woken
- * in jiffies will be returned, or 0 if the timer expired in time
+ * up.
  *
  * The current task state is guaranteed to be TASK_RUNNING when this
  * routine returns.
  * the CPU away without a bound on the timeout. In this case the return
  * value will be %MAX_SCHEDULE_TIMEOUT.
  *
- * In all cases the return value is guaranteed to be non-negative.
+ * Returns 0 when the timer has expired otherwise the remaining time in
+ * jiffies will be returned.  In all cases the return value is guaranteed
+ * to be non-negative.
  */
 signed long __sched schedule_timeout(signed long timeout)
 {
 EXPORT_SYMBOL(msleep_interruptible);
-static void __sched do_usleep_range(unsigned long min, unsigned long max)
-{
-	ktime_t kmin;
-	u64 delta;
-	kmin = ktime_set(0, min * NSEC_PER_USEC);
-	delta = (u64)(max - min) * NSEC_PER_USEC;
-	schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL);
-}
 /**
  * usleep_range - Sleep for an approximate time
  * @min: Minimum time in usecs to sleep
  */
 void __sched usleep_range(unsigned long min, unsigned long max)
 {
-	__set_current_state(TASK_UNINTERRUPTIBLE);
+	ktime_t exp = ktime_add_us(ktime_get(), min);
-	do_usleep_range(min, max);
+	u64 delta = (u64)(max - min) * NSEC_PER_USEC;
+	for (;;) {
+		__set_current_state(TASK_UNINTERRUPTIBLE);
+		/* Do not return before the requested sleep time has elapsed */
+		if (!schedule_hrtimeout_range(&exp, delta, HRTIMER_MODE_ABS))
+			break;
+	}
 }
 EXPORT_SYMBOL(usleep_range);