The patch titled
hrtimers: cleanup, state tracking update
has been removed from the -mm tree. Its filename was
updated-high-res-timers-core-cleanup-state-tracking-update.patch
This patch was dropped because it is obsolete
------------------------------------------------------
Subject: hrtimers: cleanup, state tracking update
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cleanup: address the issues which were pointed out by Arjan's review. Add
inline functions to access the state and fix comments.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/hrtimer.h | 7 +++---
kernel/hrtimer.c | 44 +++++++++++++++++++++++++-------------
2 files changed, 33 insertions(+), 18 deletions(-)
diff -puN include/linux/hrtimer.h~updated-high-res-timers-core-cleanup-state-tracking-update include/linux/hrtimer.h
--- a/include/linux/hrtimer.h~updated-high-res-timers-core-cleanup-state-tracking-update
+++ a/include/linux/hrtimer.h
@@ -59,17 +59,18 @@ enum hrtimer_cb_mode {
};
/*
- * Bit values to track state of the timer
+ * Values to track state of the timer
*
* Possible states:
*
* 0x00 inactive
* 0x01 enqueued into rbtree
* 0x02 callback function running
- * 0x03 callback function running and enqueued
- * (was requeued on another CPU)
* 0x04 callback pending (high resolution mode)
*
+ * Special case:
+ * 0x03 callback function running and enqueued
+ * (was requeued on another CPU)
* The "callback function running and enqueued" status is only possible on
* SMP. It happens for example when a posix timer expired and the callback
* queued a signal. Between dropping the lock which protects the posix timer
diff -puN kernel/hrtimer.c~updated-high-res-timers-core-cleanup-state-tracking-update kernel/hrtimer.c
--- a/kernel/hrtimer.c~updated-high-res-timers-core-cleanup-state-tracking-update
+++ a/kernel/hrtimer.c
@@ -151,6 +151,24 @@ static void hrtimer_get_softirq_time(str
}
/*
+ * Helper function to check, whether the timer is on one of the queues
+ */
+static inline int hrtimer_is_queued(struct hrtimer *timer)
+{
+ return timer->state &
+ (HRTIMER_STATE_ENQUEUED || HRTIMER_STATE_PENDING);
+}
+
+/*
+ * Helper function to check, whether the timer is running the callback
+ * function
+ */
+static inline int hrtimer_callback_running(struct hrtimer *timer)
+{
+ return timer->state & HRTIMER_STATE_CALLBACK;
+}
+
+/*
* Functions and macros which are different for UP/SMP systems are kept in a
* single place
*/
@@ -209,7 +227,7 @@ switch_hrtimer_base(struct hrtimer *time
* completed. There is no conflict as we hold the lock until
* the timer is enqueued.
*/
- if (unlikely(timer->state & HRTIMER_STATE_CALLBACK))
+ if (unlikely(hrtimer_callback_running(timer)))
return base;
/* See the comment in lock_timer_base() */
@@ -237,12 +255,6 @@ lock_hrtimer_base(const struct hrtimer *
#endif /* !CONFIG_SMP */
-static inline int hrtimer_is_queued(struct hrtimer *timer)
-{
- return timer->state != HRTIMER_STATE_INACTIVE &&
- timer->state != HRTIMER_STATE_CALLBACK;
-}
-
/*
* Functions for the union type storage format of ktime_t which are
* too large for inlining:
@@ -385,7 +397,7 @@ static int hrtimer_reprogram(struct hrti
* reprogramming is handled either by the softirq, which called the
* callback or at the end of the hrtimer_interrupt.
*/
- if (timer->state & HRTIMER_STATE_CALLBACK)
+ if (hrtimer_callback_running(timer))
return 0;
if (expires.tv64 >= expires_next->tv64)
@@ -614,7 +626,7 @@ static void hrtimer_check_clocks(void)
*/
static inline int hrtimer_cb_pending(const struct hrtimer *timer)
{
- return timer->state == HRTIMER_STATE_PENDING;
+ return timer->state & HRTIMER_STATE_PENDING;
}
/*
@@ -964,7 +976,7 @@ int hrtimer_try_to_cancel(struct hrtimer
base = lock_hrtimer_base(timer, &flags);
- if (!(timer->state & HRTIMER_STATE_CALLBACK))
+ if (!hrtimer_callback_running(timer))
ret = remove_hrtimer(timer, base);
unlock_hrtimer_base(timer, &flags);
@@ -1153,12 +1165,14 @@ void hrtimer_interrupt(struct pt_regs *r
__remove_hrtimer(timer, base,
HRTIMER_STATE_CALLBACK, 0);
+ /*
+ * Note: We clear the CALLBACK bit after
+ * enqueue_hrtimer to avoid reprogramming of
+ * the event hardware. This happens at the end
+ * of this function anyway.
+ */
if (timer->function(timer) != HRTIMER_NORESTART) {
BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
- /*
- * Do not reprogram. We do this when we break
- * out of the loop !
- */
enqueue_hrtimer(timer, base, 0);
}
timer->state &= ~HRTIMER_STATE_CALLBACK;
@@ -1442,7 +1456,7 @@ static void migrate_hrtimer_list(struct
while ((node = rb_first(&old_base->active))) {
timer = rb_entry(node, struct hrtimer, node);
- BUG_ON(timer->state & HRTIMER_STATE_CALLBACK);
+ BUG_ON(hrtimer_callback_running(timer));
__remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0);
timer->base = new_base;
/*
_
Patches currently in -mm which might be from tglx@xxxxxxxxxxxxx are
origin.patch
git-mtd.patch
gtod-uninline-jiffiesh.patch
gtod-fix-multiple-conversion-bugs-in-msecs_to_jiffies.patch
gtod-fix-timeout-overflow.patch
gtod-persistent-clock-support-core.patch
gtod-persistent-clock-support-i386.patch
dynticks-uninline-irq_enter.patch
dynticks-extend-next_timer_interrupt-to-use-a-reference-jiffie.patch
hrtimers-namespace-and-enum-cleanup.patch
hrtimers-clean-up-locking.patch
hrtimers-add-state-tracking.patch
hrtimers-clean-up-callback-tracking.patch
hrtimers-move-and-add-documentation.patch
acpi-include-fix.patch
acpi-keep-track-of-timer-broadcast.patch
acpi-add-state-propagation-for-dynamic-broadcasting.patch
acpi-cleanups-allow-early-access-to-pmtimer.patch
i386-apic-clean-up-the-apic-code.patch
clockevents-core.patch
clockevents-i386-drivers.patch
clockevents-i386-hpet-driver.patch
i386-apic-rework-and-fix-local-apic-calibration.patch
high-res-timers-core.patch
high-res-timers-core-do-itimer-rearming-in-process-context.patch
high-res-timers-allow-tsc-clocksource-if-pmtimer-present.patch
dynticks-core.patch
dynticks-add-nohz-stats-to-proc-stat.patch
dynticks-i386-support-idle-handler-callbacks.patch
dynticks-i386-prepare-nmi-watchdog.patch
high-res-timers-dynticks-i386-support-enable-in-kconfig.patch
debugging-feature-add-proc-timer_stat.patch
-
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