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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/back_to_back_ebbs_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/back_to_back_ebbs_test.c')
-rw-r--r--kernel/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/kernel/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c b/kernel/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c
new file mode 100644
index 000000000..66ea765c0
--- /dev/null
+++ b/kernel/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2014, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "ebb.h"
+
+
+#define NUMBER_OF_EBBS 50
+
+/*
+ * Test that if we overflow the counter while in the EBB handler, we take
+ * another EBB on exiting from the handler.
+ *
+ * We do this by counting with a stupidly low sample period, causing us to
+ * overflow the PMU while we're still in the EBB handler, leading to another
+ * EBB.
+ *
+ * We get out of what would otherwise be an infinite loop by leaving the
+ * counter frozen once we've taken enough EBBs.
+ */
+
+static void ebb_callee(void)
+{
+ uint64_t siar, val;
+
+ val = mfspr(SPRN_BESCR);
+ if (!(val & BESCR_PMEO)) {
+ ebb_state.stats.spurious++;
+ goto out;
+ }
+
+ ebb_state.stats.ebb_count++;
+ trace_log_counter(ebb_state.trace, ebb_state.stats.ebb_count);
+
+ /* Resets the PMC */
+ count_pmc(1, sample_period);
+
+out:
+ if (ebb_state.stats.ebb_count == NUMBER_OF_EBBS)
+ /* Reset but leave counters frozen */
+ reset_ebb_with_clear_mask(MMCR0_PMAO);
+ else
+ /* Unfreezes */
+ reset_ebb();
+
+ /* Do some stuff to chew some cycles and pop the counter */
+ siar = mfspr(SPRN_SIAR);
+ trace_log_reg(ebb_state.trace, SPRN_SIAR, siar);
+
+ val = mfspr(SPRN_PMC1);
+ trace_log_reg(ebb_state.trace, SPRN_PMC1, val);
+
+ val = mfspr(SPRN_MMCR0);
+ trace_log_reg(ebb_state.trace, SPRN_MMCR0, val);
+}
+
+int back_to_back_ebbs(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(ebb_callee);
+
+ FAIL_IF(ebb_event_enable(&event));
+
+ sample_period = 5;
+
+ ebb_freeze_pmcs();
+ mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
+ ebb_global_enable();
+ ebb_unfreeze_pmcs();
+
+ while (ebb_state.stats.ebb_count < NUMBER_OF_EBBS)
+ FAIL_IF(core_busy_loop());
+
+ ebb_global_disable();
+ ebb_freeze_pmcs();
+
+ count_pmc(1, sample_period);
+
+ dump_ebb_state();
+
+ event_close(&event);
+
+ FAIL_IF(ebb_state.stats.ebb_count != NUMBER_OF_EBBS);
+
+ return 0;
+}
+
+int main(void)
+{
+ return test_harness(back_to_back_ebbs, "back_to_back_ebbs");
+}