Excerpt from man 2 perf_event_open:
/proc/sys/kernel/perf_event_paranoid
The perf_event_paranoid file can be set to restrict access to the
performance counters.
2 allow only user-space measurements.
1 allow both kernel and user measurements (default).
0 allow access to CPU-specific data but not raw tracepoint samples.
-1 no restrictions.
require_paranoia_below() should return 0 if perf_event_paranoid is below
a specified level, the value from perf_event_paranoid is read into an
unsigned long so the incorrect value is returned when
perf_event_paranoid is set to -1.
Without this patch applied there is the same number of selftests/powerpc
which skip when /proc/sys/kernel/perf_event_paranoid is set to 1 or -1
but no skips when set to zero.
With this patch applied there are no skipped selftests/powerpc test when
/proc/sys/kernel/perf_event_paranoid is set to 0 or -1.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We want to use this in another test, so make it available at the top of
the powerpc selftests tree.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move get_auxv_entry() from pmu/lib.c up to harness.c in order to make
it available to other tests.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The Power8 Performance Monitor Unit (PMU) has a new feature called Event
Based Branches (EBB). This commit adds tests of the kernel API for using
EBBs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
