[PATCH] Fix for 'make distcheck' failure: Make map_event_to_counter handle a non-native cpu_type

[Maynard J. <may...@us...>]

We recently discovered that 'make distcheck' fails the 
libop/tests/allocate_counter_tests.  This testcase dummies up some events for 
various cpu types and uses map_event_to_counter to try to verify the allocation 
of the events to counters.  For each invocation of map_event_to_counter, the 
testcase passes in the cpu_type it's doing the test on. A problem occurs because 
map_event_to_counter computes nr_counters by scanning /dev/oprofile, looking for 
*native* counter files in oprofilefs.  If the number of native counter files is 
less than what is defined for the number of counters for the passed cpu_type, 
then the testcase fails.

Besides allocate_counter_tests, I also found that ophelp calls 
map_event_to_counter and can potentially pass in a non-native cpu_type.  With 
the right (or maybe I should say "wrong") selection of cpu_type and events, 
ophelp will fail in the same way that allocate_counter_tests fails.

The attached patch fixes map_event_to_counter so that it recognizes when the 
passed cpu_type is not the native cpu_type and won't try to use the native 
counter files in /dev/oprofile.

Suravee, can you please review and test this patch.

Signed-off-by: Maynard Johnson <may...@us...>

-Maynard