mirror of
https://github.com/adulau/aha.git
synced 2024-12-28 03:36:19 +00:00
681405bfc7
The current code tries to optimize the setting of KVM_REQ_PENDING_TIMER but used atomic_inc_and_test - which always returns true unless pending had the invalid value of -1 on entry. This patch drops the test part preserving the original semantic but expressing it less confusingly. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
50 lines
1.2 KiB
C
50 lines
1.2 KiB
C
#include <linux/kvm_host.h>
|
|
#include <linux/kvm.h>
|
|
#include <linux/hrtimer.h>
|
|
#include <asm/atomic.h>
|
|
#include "kvm_timer.h"
|
|
|
|
static int __kvm_timer_fn(struct kvm_vcpu *vcpu, struct kvm_timer *ktimer)
|
|
{
|
|
int restart_timer = 0;
|
|
wait_queue_head_t *q = &vcpu->wq;
|
|
|
|
/*
|
|
* There is a race window between reading and incrementing, but we do
|
|
* not care about potentially loosing timer events in the !reinject
|
|
* case anyway.
|
|
*/
|
|
if (ktimer->reinject || !atomic_read(&ktimer->pending)) {
|
|
atomic_inc(&ktimer->pending);
|
|
/* FIXME: this code should not know anything about vcpus */
|
|
set_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
|
|
}
|
|
|
|
if (waitqueue_active(q))
|
|
wake_up_interruptible(q);
|
|
|
|
if (ktimer->t_ops->is_periodic(ktimer)) {
|
|
hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
|
|
restart_timer = 1;
|
|
}
|
|
|
|
return restart_timer;
|
|
}
|
|
|
|
enum hrtimer_restart kvm_timer_fn(struct hrtimer *data)
|
|
{
|
|
int restart_timer;
|
|
struct kvm_vcpu *vcpu;
|
|
struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
|
|
|
|
vcpu = ktimer->vcpu;
|
|
if (!vcpu)
|
|
return HRTIMER_NORESTART;
|
|
|
|
restart_timer = __kvm_timer_fn(vcpu, ktimer);
|
|
if (restart_timer)
|
|
return HRTIMER_RESTART;
|
|
else
|
|
return HRTIMER_NORESTART;
|
|
}
|
|
|