From: Avi Kivity <avi@xxxxxxxxxx>
'nr_cpus_done' is not incremented atomically; this has been observed to
cause tests to stall. Fix by using a proper atomic increment.
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
diff --git a/x86/vmexit.c b/x86/vmexit.c
index 875caa3..ad8ab55 100644
--- a/x86/vmexit.c
+++ b/x86/vmexit.c
@@ -2,6 +2,7 @@
#include "libcflat.h"
#include "smp.h"
#include "processor.h"
+#include "atomic.h"
static unsigned int inl(unsigned short port)
{
@@ -121,7 +122,7 @@ static struct test {
};
unsigned iterations;
-volatile int nr_cpus_done;
+static atomic_t nr_cpus_done;
static void run_test(void *_func)
{
@@ -131,7 +132,7 @@ static void run_test(void *_func)
for (i = 0; i < iterations; ++i)
func();
- nr_cpus_done++;
+ atomic_inc(&nr_cpus_done);
}
static void do_test(struct test *test)
@@ -155,10 +156,10 @@ static void do_test(struct test *test)
for (i = 0; i < iterations; ++i)
func();
} else {
- nr_cpus_done = 0;
+ atomic_set(&nr_cpus_done, 0);
for (i = cpu_count(); i > 0; i--)
on_cpu_async(i-1, run_test, func);
- while (nr_cpus_done < cpu_count())
+ while (atomic_read(&nr_cpus_done) < cpu_count())
;
}
t2 = rdtsc();
--
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