Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-27 14:41:39 +00:00
Code Issues Packages Projects Releases Wiki Activity

tick: broadcast: Simplify oneshot logic and shorten lock region

Browse Source 
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@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2015-05-05 09:44:24 +02:00
parent 2951d5c031
commit 298dbd1c5c
1 changed files with 17 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
kernel/time/tick-broadcast.c
View File

@ -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 {