test/test_xcall: update to trigger local APIC init race

1 files changed, 10 insertions, 3 deletions

diff --git a/test/test_xcall.c b/test/test_xcall.c
index 6de73a00..49706cde 100644
--- a/test/test_xcall.c
+++ b/test/test_xcall.c
@@ -70,7 +70,7 @@ test_run_cpu(void *arg)
 {
     (void)arg;
 
-    for (unsigned int i = 0; i < cpu_count(); i++) {
+    for (unsigned int i = (cpu_count() - 1); i < cpu_count(); i++) {
         test_once(i);
     }
 }
@@ -82,6 +82,7 @@ test_run(void *arg)
     struct thread_attr attr;
     struct thread *thread;
     struct cpumap *cpumap;
+    unsigned int cpu;
     int error;
 
     (void)arg;
@@ -90,9 +91,15 @@ test_run(void *arg)
     error_check(error, "cpumap_create");
 
     for (unsigned int i = 0; i < cpu_count(); i++) {
+        /*
+         * FIXME There seems to be an initialization race of the local APIC when
+         * sending IPIs early from CPU 1 to CPU 2 or more.
+         */
+        cpu = (1 + i) % cpu_count();
+
         cpumap_zero(cpumap);
-        cpumap_set(cpumap, i);
-        snprintf(name, sizeof(name), THREAD_KERNEL_PREFIX "test_run/%u", i);
+        cpumap_set(cpumap, cpu);
+        snprintf(name, sizeof(name), THREAD_KERNEL_PREFIX "test_run/%u", cpu);
         thread_attr_init(&attr, name);
         thread_attr_set_cpumap(&attr, cpumap);
         error = thread_create(&thread, &attr, test_run_cpu, NULL);