x86/cpu: turn cpu_delay into a compiler barrier

2 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/machine/cpu.c b/arch/x86/machine/cpu.c
index 225f6483..5eb9ce2d 100644
--- a/arch/x86/machine/cpu.c
+++ b/arch/x86/machine/cpu.c
@@ -416,6 +416,7 @@ cpu_delay(unsigned long usecs)
         diff = count - prev;
         prev = count;
         total -= diff;
+        cpu_pause();
     } while (total > 0);
 }
 
diff --git a/arch/x86/machine/cpu.h b/arch/x86/machine/cpu.h
index 78857cdc..b94c149d 100644
--- a/arch/x86/machine/cpu.h
+++ b/arch/x86/machine/cpu.h
@@ -594,6 +594,8 @@ uint64_t cpu_get_freq(void);
 
 /*
  * Busy-wait for a given amount of time, in microseconds.
+ *
+ * Implies a compiler barrier.
  */
 void cpu_delay(unsigned long usecs);