Commit-ID: 298dbd1c5cd66f0ac85981b83b7d519a5d88d1b8
Gitweb: http://git.kernel.org/tip/298dbd1c5cd66f0ac85981b83b7d519a5d88d1b8
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Tue, 5 May 2015 09:44:24 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 5 May 2015 10:25:23 +0200
tick: broadcast: Simplify oneshot logic and shorten lock region
Simplify the oneshot logic by avoiding the reprogramming loops. That
also allows to call the cpu local handler outside of the
broadcast_lock held region.
Tested-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/time/tick-broadcast.c | 42 +++++++++++++++++-------------------------
1 file changed, 17 insertions(+), 25 deletions(-)
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 5d9e4aa..12fcc55 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -525,18 +525,14 @@ static void tick_broadcast_set_affinity(struct clock_event_device *bc,
irq_set_affinity(bc->irq, bc->cpumask);
}
-static int tick_broadcast_set_event(struct clock_event_device *bc, int cpu,
- ktime_t expires, int force)
+static void tick_broadcast_set_event(struct clock_event_device *bc, int cpu,
+ ktime_t expires)
{
- int ret;
-
if (bc->state != CLOCK_EVT_STATE_ONESHOT)
clockevents_set_state(bc, CLOCK_EVT_STATE_ONESHOT);
- ret = clockevents_program_event(bc, expires, force);
- if (!ret)
- tick_broadcast_set_affinity(bc, cpumask_of(cpu));
- return ret;
+ clockevents_program_event(bc, expires, 1);
+ tick_broadcast_set_affinity(bc, cpumask_of(cpu));
}
static void tick_resume_broadcast_oneshot(struct clock_event_device *bc)
@@ -573,9 +569,9 @@ static void tick_handle_oneshot_broadcast(struct clock_event_device *dev)
struct tick_device *td;
ktime_t now, next_event;
int cpu, next_cpu = 0;
+ bool bc_local;
raw_spin_lock(&tick_broadcast_lock);
-again:
dev->next_event.tv64 = KTIME_MAX;
next_event.tv64 = KTIME_MAX;
cpumask_clear(tmpmask);
@@ -615,13 +611,9 @@ again:
cpumask_and(tmpmask, tmpmask, cpu_online_mask);
/*
- * Wakeup the cpus which have an expired event and handle the
- * broadcast event of the local cpu.
+ * Wakeup the cpus which have an expired event.
*/
- if (tick_do_broadcast(tmpmask)) {
- td = this_cpu_ptr(&tick_cpu_device);
- td->evtdev->event_handler(td->evtdev);
- }
+ bc_local = tick_do_broadcast(tmpmask);
/*
* Two reasons for reprogram:
@@ -633,15 +625,15 @@ again:
* - There are pending events on sleeping CPUs which were not
* in the event mask
*/
- if (next_event.tv64 != KTIME_MAX) {
- /*
- * Rearm the broadcast device. If event expired,
- * repeat the above
- */
- if (tick_broadcast_set_event(dev, next_cpu, next_event, 0))
- goto again;
- }
+ if (next_event.tv64 != KTIME_MAX)
+ tick_broadcast_set_event(dev, next_cpu, next_event);
+
raw_spin_unlock(&tick_broadcast_lock);
+
+ if (bc_local) {
+ td = this_cpu_ptr(&tick_cpu_device);
+ td->evtdev->event_handler(td->evtdev);
+ }
}
static int broadcast_needs_cpu(struct clock_event_device *bc, int cpu)
@@ -723,7 +715,7 @@ int tick_broadcast_oneshot_control(enum tick_broadcast_state state)
*/
if (!cpumask_test_cpu(cpu, tick_broadcast_force_mask) &&
dev->next_event.tv64 < bc->next_event.tv64)
- tick_broadcast_set_event(bc, cpu, dev->next_event, 1);
+ tick_broadcast_set_event(bc, cpu, dev->next_event);
}
/*
* If the current CPU owns the hrtimer broadcast
@@ -858,7 +850,7 @@ void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
clockevents_set_state(bc, CLOCK_EVT_STATE_ONESHOT);
tick_broadcast_init_next_event(tmpmask,
tick_next_period);
- tick_broadcast_set_event(bc, cpu, tick_next_period, 1);
+ tick_broadcast_set_event(bc, cpu, tick_next_period);
} else
bc->next_event.tv64 = KTIME_MAX;
} else {
--
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