perf_counter tools: increase limits, fix

NR_CPUS and NR_COUNTERS goes up quadratic ... 1024x4096 was far
too ambitious upper limit - go for 256x256 which is still plenty.

[ Impact: reduce perf tool memory consumption ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Documentation/perf_counter/perf.h

@@ -61,8 +61,8 @@ sys_perf_counter_open(struct perf_counter_hw_event *hw_event_uptr,
 		       group_fd, flags);
 }
 
-#define MAX_COUNTERS			1024
-#define MAX_NR_CPUS			4096
+#define MAX_COUNTERS			256
+#define MAX_NR_CPUS			256
 
 #define EID(type, id) (((__u64)(type) << PERF_COUNTER_TYPE_SHIFT) | (id))