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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c')
-rw-r--r--kernel/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/kernel/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c b/kernel/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c
new file mode 100644
index 000000000..986500fd2
--- /dev/null
+++ b/kernel/tools/testing/selftests/powerpc/pmu/ebb/pmae_handling_test.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2014, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#include <sched.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "ebb.h"
+
+
+/*
+ * Test that the kernel properly handles PMAE across context switches.
+ *
+ * We test this by calling into the kernel inside our EBB handler, where PMAE
+ * is clear. A cpu eater companion thread is running on the same CPU as us to
+ * encourage the scheduler to switch us.
+ *
+ * The kernel must make sure that when it context switches us back in, it
+ * honours the fact that we had PMAE clear.
+ *
+ * Observed to hit the failing case on the first EBB with a broken kernel.
+ */
+
+static bool mmcr0_mismatch;
+static uint64_t before, after;
+
+static void syscall_ebb_callee(void)
+{
+ uint64_t val;
+
+ val = mfspr(SPRN_BESCR);
+ if (!(val & BESCR_PMEO)) {
+ ebb_state.stats.spurious++;
+ goto out;
+ }
+
+ ebb_state.stats.ebb_count++;
+ count_pmc(1, sample_period);
+
+ before = mfspr(SPRN_MMCR0);
+
+ /* Try and get ourselves scheduled, to force a PMU context switch */
+ sched_yield();
+
+ after = mfspr(SPRN_MMCR0);
+ if (before != after)
+ mmcr0_mismatch = true;
+
+out:
+ reset_ebb();
+}
+
+static int test_body(void)
+{
+ struct event event;
+
+ event_init_named(&event, 0x1001e, "cycles");
+ event_leader_ebb_init(&event);
+
+ event.attr.exclude_kernel = 1;
+ event.attr.exclude_hv = 1;
+ event.attr.exclude_idle = 1;
+
+ FAIL_IF(event_open(&event));
+
+ setup_ebb_handler(syscall_ebb_callee);
+ ebb_global_enable();
+
+ FAIL_IF(ebb_event_enable(&event));
+
+ mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
+
+ while (ebb_state.stats.ebb_count < 20 && !mmcr0_mismatch)
+ FAIL_IF(core_busy_loop());
+
+ ebb_global_disable();
+ ebb_freeze_pmcs();
+
+ count_pmc(1, sample_period);
+
+ dump_ebb_state();
+
+ if (mmcr0_mismatch)
+ printf("Saw MMCR0 before 0x%lx after 0x%lx\n", before, after);
+
+ event_close(&event);
+
+ FAIL_IF(ebb_state.stats.ebb_count == 0);
+ FAIL_IF(mmcr0_mismatch);
+
+ return 0;
+}
+
+int pmae_handling(void)
+{
+ return eat_cpu(test_body);
+}
+
+int main(void)
+{
+ return test_harness(pmae_handling, "pmae_handling");
+}