selftests/powerpc: PMU libs: use signed long to read perf_event_paranoid

Michael Ellerman mpe at
Wed Jul 6 00:10:18 AEST 2016

On Tue, 2016-01-03 at 04:26:36 UTC, Cyril Bur wrote:
> 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 no skipped selftests/powerpc test when
> /proc/sys/kernel/perf_event_paranoid is set to 0 or -1.
> Signed-off-by: Cyril Bur <cyrilbur at>

Applied to powerpc next, thanks.


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