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-rw-r--r--cpus.c25
1 files changed, 17 insertions, 8 deletions
diff --git a/cpus.c b/cpus.c
index 85cd451a86..d2c61ff155 100644
--- a/cpus.c
+++ b/cpus.c
@@ -77,6 +77,8 @@
#endif /* CONFIG_LINUX */
+static QemuMutex qemu_global_mutex;
+
int64_t max_delay;
int64_t max_advance;
@@ -782,7 +784,7 @@ static void cpu_throttle_thread(CPUState *cpu, run_on_cpu_data opaque)
{
double pct;
double throttle_ratio;
- long sleeptime_ns;
+ int64_t sleeptime_ns, endtime_ns;
if (!cpu_throttle_get_percentage()) {
return;
@@ -790,11 +792,20 @@ static void cpu_throttle_thread(CPUState *cpu, run_on_cpu_data opaque)
pct = (double)cpu_throttle_get_percentage()/100;
throttle_ratio = pct / (1 - pct);
- sleeptime_ns = (long)(throttle_ratio * CPU_THROTTLE_TIMESLICE_NS);
-
- qemu_mutex_unlock_iothread();
- g_usleep(sleeptime_ns / 1000); /* Convert ns to us for usleep call */
- qemu_mutex_lock_iothread();
+ /* Add 1ns to fix double's rounding error (like 0.9999999...) */
+ sleeptime_ns = (int64_t)(throttle_ratio * CPU_THROTTLE_TIMESLICE_NS + 1);
+ endtime_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + sleeptime_ns;
+ while (sleeptime_ns > 0 && !cpu->stop) {
+ if (sleeptime_ns > SCALE_MS) {
+ qemu_cond_timedwait(cpu->halt_cond, &qemu_global_mutex,
+ sleeptime_ns / SCALE_MS);
+ } else {
+ qemu_mutex_unlock_iothread();
+ g_usleep(sleeptime_ns / SCALE_US);
+ qemu_mutex_lock_iothread();
+ }
+ sleeptime_ns = endtime_ns - qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+ }
atomic_set(&cpu->throttle_thread_scheduled, 0);
}
@@ -1172,8 +1183,6 @@ static void qemu_init_sigbus(void)
}
#endif /* !CONFIG_LINUX */
-static QemuMutex qemu_global_mutex;
-
static QemuThread io_thread;
/* cpu creation */