timer/cpus: fix some typos and update some comments

[qemu.git] / cpus.c

diff --git a/cpus.c b/cpus.c
index 3e3ef95e381a190f112735d82c15046e795233b4..0ab4ab1ef21dca80bfca8ad69d6b96c0431bc396 100644 (file)
--- a/cpus.c
+++ b/cpus.c
@@ -229,7 +229,7 @@ static int64_t cpu_get_clock_locked(void)
     return ticks;
 }
 
-/* return the host CPU monotonic timer and handle stop/restart */
+/* return the host CPU monotonic time */
 int64_t cpu_get_clock(void)
 {
     int64_t ti;
@@ -244,34 +244,34 @@ int64_t cpu_get_clock(void)
 }
 
 /* enable cpu_get_ticks()
- * Caller must hold BQL which server as mutex for vm_clock_seqlock.
+ * Caller must hold BQL which serves as mutex for vm_clock_seqlock.
  */
 void cpu_enable_ticks(void)
 {
     /* Here, the really thing protected by seqlock is cpu_clock_offset. */
-    seqlock_write_lock(&timers_state.vm_clock_seqlock);
+    seqlock_write_begin(&timers_state.vm_clock_seqlock);
     if (!timers_state.cpu_ticks_enabled) {
         timers_state.cpu_ticks_offset -= cpu_get_host_ticks();
         timers_state.cpu_clock_offset -= get_clock();
         timers_state.cpu_ticks_enabled = 1;
     }
-    seqlock_write_unlock(&timers_state.vm_clock_seqlock);
+    seqlock_write_end(&timers_state.vm_clock_seqlock);
 }
 
 /* disable cpu_get_ticks() : the clock is stopped. You must not call
  * cpu_get_ticks() after that.
- * Caller must hold BQL which server as mutex for vm_clock_seqlock.
+ * Caller must hold BQL which serves as mutex for vm_clock_seqlock.
  */
 void cpu_disable_ticks(void)
 {
     /* Here, the really thing protected by seqlock is cpu_clock_offset. */
-    seqlock_write_lock(&timers_state.vm_clock_seqlock);
+    seqlock_write_begin(&timers_state.vm_clock_seqlock);
     if (timers_state.cpu_ticks_enabled) {
         timers_state.cpu_ticks_offset += cpu_get_host_ticks();
         timers_state.cpu_clock_offset = cpu_get_clock_locked();
         timers_state.cpu_ticks_enabled = 0;
     }
-    seqlock_write_unlock(&timers_state.vm_clock_seqlock);
+    seqlock_write_end(&timers_state.vm_clock_seqlock);
 }
 
 /* Correlation between real and virtual time is always going to be
@@ -294,7 +294,7 @@ static void icount_adjust(void)
         return;
     }
 
-    seqlock_write_lock(&timers_state.vm_clock_seqlock);
+    seqlock_write_begin(&timers_state.vm_clock_seqlock);
     cur_time = cpu_get_clock_locked();
     cur_icount = cpu_get_icount_locked();
 
@@ -315,7 +315,7 @@ static void icount_adjust(void)
     last_delta = delta;
     timers_state.qemu_icount_bias = cur_icount
                               - (timers_state.qemu_icount << icount_time_shift);
-    seqlock_write_unlock(&timers_state.vm_clock_seqlock);
+    seqlock_write_end(&timers_state.vm_clock_seqlock);
 }
 
 static void icount_adjust_rt(void *opaque)
@@ -355,7 +355,7 @@ static void icount_warp_rt(void)
         return;
     }
 
-    seqlock_write_lock(&timers_state.vm_clock_seqlock);
+    seqlock_write_begin(&timers_state.vm_clock_seqlock);
     if (runstate_is_running()) {
         int64_t clock = REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT,
                                      cpu_get_clock_locked());
@@ -374,7 +374,7 @@ static void icount_warp_rt(void)
         timers_state.qemu_icount_bias += warp_delta;
     }
     vm_clock_warp_start = -1;
-    seqlock_write_unlock(&timers_state.vm_clock_seqlock);
+    seqlock_write_end(&timers_state.vm_clock_seqlock);
 
     if (qemu_clock_expired(QEMU_CLOCK_VIRTUAL)) {
         qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
@@ -399,9 +399,9 @@ void qtest_clock_warp(int64_t dest)
         int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
         int64_t warp = qemu_soonest_timeout(dest - clock, deadline);
 
-        seqlock_write_lock(&timers_state.vm_clock_seqlock);
+        seqlock_write_begin(&timers_state.vm_clock_seqlock);
         timers_state.qemu_icount_bias += warp;
-        seqlock_write_unlock(&timers_state.vm_clock_seqlock);
+        seqlock_write_end(&timers_state.vm_clock_seqlock);
 
         qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL);
         timerlist_run_timers(aio_context->tlg.tl[QEMU_CLOCK_VIRTUAL]);
@@ -468,9 +468,9 @@ void qemu_start_warp_timer(void)
              * It is useful when we want a deterministic execution time,
              * isolated from host latencies.
              */
-            seqlock_write_lock(&timers_state.vm_clock_seqlock);
+            seqlock_write_begin(&timers_state.vm_clock_seqlock);
             timers_state.qemu_icount_bias += deadline;
-            seqlock_write_unlock(&timers_state.vm_clock_seqlock);
+            seqlock_write_end(&timers_state.vm_clock_seqlock);
             qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
         } else {
             /*
@@ -481,11 +481,11 @@ void qemu_start_warp_timer(void)
              * you will not be sending network packets continuously instead of
              * every 100ms.
              */
-            seqlock_write_lock(&timers_state.vm_clock_seqlock);
+            seqlock_write_begin(&timers_state.vm_clock_seqlock);
             if (vm_clock_warp_start == -1 || vm_clock_warp_start > clock) {
                 vm_clock_warp_start = clock;
             }
-            seqlock_write_unlock(&timers_state.vm_clock_seqlock);
+            seqlock_write_end(&timers_state.vm_clock_seqlock);
             timer_mod_anticipate(icount_warp_timer, clock + deadline);
         }
     } else if (deadline == 0) {
@@ -621,7 +621,7 @@ int cpu_throttle_get_percentage(void)
 
 void cpu_ticks_init(void)
 {
-    seqlock_init(&timers_state.vm_clock_seqlock, NULL);
+    seqlock_init(&timers_state.vm_clock_seqlock);
     vmstate_register(NULL, 0, &vmstate_timers, &timers_state);
     throttle_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT,
                                            cpu_throttle_timer_tick, NULL);
@@ -1084,6 +1084,8 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
     } while (!cpu->unplug || cpu_can_run(cpu));
 
     qemu_kvm_destroy_vcpu(cpu);
+    cpu->created = false;
+    qemu_cond_signal(&qemu_cpu_cond);
     qemu_mutex_unlock_iothread();
     return NULL;
 }
@@ -1184,6 +1186,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
         }
         if (remove_cpu) {
             qemu_tcg_destroy_vcpu(remove_cpu);
+            cpu->created = false;
+            qemu_cond_signal(&qemu_cpu_cond);
             remove_cpu = NULL;
         }
     }
@@ -1349,6 +1353,14 @@ void cpu_remove(CPUState *cpu)
     qemu_cpu_kick(cpu);
 }
 
+void cpu_remove_sync(CPUState *cpu)
+{
+    cpu_remove(cpu);
+    while (cpu->created) {
+        qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
+    }
+}
+
 /* For temporary buffers for forming a name */
 #define VCPU_THREAD_NAME_SIZE 16