sim-card
/
qemu
Archived
10
0
Fork 0
Code Releases Activity

kvm specific wait_io_event 

In KVM mode the global mutex is released when vcpus are executing,
which means acquiring the fairness mutex is not required.

Also for KVM there is one thread per vcpu, so tcg_has_work is meaningless.

Add a new qemu_wait_io_event_common function to hold common code
between TCG/KVM.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Marcelo Tosatti 2010-02-17 20:14:41 -02:00 committed by Avi Kivity
parent adc8c965c4
commit fed6c3444c
1 changed files with 20 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
vl.c
View File

@ -3383,6 +3383,7 @@ static QemuCond qemu_pause_cond;
static void block_io_signals(void);
static void unblock_io_signals(void);
static int tcg_has_work(void);
static int cpu_has_work(CPUState *env);
static int qemu_init_main_loop(void)
{
@ -3403,6 +3404,15 @@ static int qemu_init_main_loop(void)
return 0;
}
static void qemu_wait_io_event_common(CPUState *env)
{
if (env->stop) {
env->stop = 0;
env->stopped = 1;
qemu_cond_signal(&qemu_pause_cond);
}
}
static void qemu_wait_io_event(CPUState *env)
{
while (!tcg_has_work())
@ -3419,11 +3429,15 @@ static void qemu_wait_io_event(CPUState *env)
qemu_mutex_unlock(&qemu_fair_mutex);
qemu_mutex_lock(&qemu_global_mutex);
if (env->stop) {
env->stop = 0;
env->stopped = 1;
qemu_cond_signal(&qemu_pause_cond);
}
qemu_wait_io_event_common(env);
}
static void qemu_kvm_wait_io_event(CPUState *env)
{
while (!cpu_has_work(env))
qemu_cond_timedwait(env->halt_cond, &qemu_global_mutex, 1000);
qemu_wait_io_event_common(env);
}
static int qemu_cpu_exec(CPUState *env);
@ -3449,7 +3463,7 @@ static void *kvm_cpu_thread_fn(void *arg)
while (1) {
if (cpu_can_run(env))
qemu_cpu_exec(env);
qemu_wait_io_event(env);
qemu_kvm_wait_io_event(env);
}
return NULL;