tests/perf_pmu: Handle CPU hotplug failures better

CPU hotplug, especially CPU0, can be flaky on commodity hardware.

To improve test reliability and reponse times when testing larger runs we
need to handle those cases better.

Handle failures to off-line a CPU by immediately skipping the test, and
failures to on-line a CPU by immediately rebooting the machine.

This patch includes igt_sysrq_reboot implementation from Chris Wilson.

v2: Halt by default, reboot if env variable IGT_REBOOT_ON_FATAL_ERROR is
    set. (Petri Latvala)

v3: Add missign docs and update stale comment. (Petri Latvala)

v4: Use pause instead of sleep. (Chris Wilson)
v5: Newlines! (Chris Wilson)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Petri Latvala <petri.latvala@intel.com>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Reviewed-by: Petri Latvala <petri.latvala@intel.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/lib/igt_sysrq.h b/lib/igt_sysrq.h
new file mode 100644
index 00000000..422473d2
--- /dev/null
+++ b/lib/igt_sysrq.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright © 2018 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef __IGT_SYSRQ_H__
+#define __IGT_SYSRQ_H__
+
+void igt_sysrq_reboot(void) __attribute__((noreturn));
+
+#endif /* __IGT_SYSRQ_H__ */