Glad to see you fixed the PPC problem.

On Thu, Feb 16, 2012 at 5:57 AM, Paul Mackerras [off-list ref] wrote:

On Thu, Feb 16, 2012 at 03:48:22PM +1100, Anton Blanchard wrote:

quoted

perf on POWER stopped working after commit e050e3f0a71b (perf: Fix
broken interrupt rate throttling). That patch exposed a bug in
the POWER perf_events code.

Since the PMCs count upwards and take an exception when the top bit
is set, we want to write 0x80000000 - left in power_pmu_start. We were
instead programming in left which effectively disables the counter
until we eventually hit 0x80000000. This could take seconds or longer.

With the patch applied I get the expected number of samples:

# taskset -c 0 yes > /dev/null &
# perf record -C 0 -a sleep 10
# perf report -D | grep SAMPLE | tail -1
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 SAMPLE events: =C2=A0 =C2=A0 =C2=A0 9=

948

quoted

Signed-off-by: Anton Blanchard <redacted>

Acked-by: Paul Mackerras <redacted>