perf session: Make events_stats u64 to avoid overflow on 32-bit arches

Pekka Enberg reported weird percentages in perf report. It
turns out we are overflowing a 32-bit variables in struct
events_stats on 32-bit architectures.

Before:

 [acme@ana linux-2.6-tip]$ perf report -i pekka.perf.data 2> /dev/null | head -10
   281.96%       Xorg                        b710a561  [.] 0x000000b710a561
   140.15%       Xorg  [kernel]                        [k] __initramfs_end
    51.56%   metacity  libgobject-2.0.so.0.2000.1      [.] 0x00000000026e46
    35.12%  evolution  libcairo.so.2.10800.6           [.] 0x000000000203bd
    33.84%   metacity  libpthread-2.9.so               [.] 0x00000000007a3d

After:

 [acme@ana linux-2.6-tip]$ perf report -i pekka.perf.data 2> /dev/null | head -10
    30.04%       Xorg                       b710a561   [.] 0x000000b710a561
    14.93%       Xorg  [kernel]                        [k] __initramfs_end
     5.49%   metacity  libgobject-2.0.so.0.2000.1      [.] 0x00000000026e46
     3.74%  evolution  libcairo.so.2.10800.6           [.] 0x000000000203bd
     3.61%   metacity  libpthread-2.9.so               [.] 0x00000000007a3d

Reported-by: Pekka Enberg <[email protected]>
Tested-by: Pekka Enberg <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Paul Mackerras <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

tools/perf/builtin-report.c

@@ -224,7 +224,7 @@ static int __cmd_report(void)
 
 	perf_session__collapse_resort(session);
 	perf_session__output_resort(session, session->events_stats.total);
-	fprintf(stdout, "# Samples: %ld\n#\n", session->events_stats.total);
+	fprintf(stdout, "# Samples: %Ld\n#\n", session->events_stats.total);
 	perf_session__fprintf_hists(session, NULL, false, stdout);
 	if (sort_order == default_sort_order &&
 	    parent_pattern == default_parent_pattern)

tools/perf/util/event.h

@@ -95,8 +95,8 @@ typedef union event_union {
 } event_t;
 
 struct events_stats {
-	unsigned long total;
-	unsigned long lost;
+	u64 total;
+	u64 lost;
 };
 
 void event__print_totals(void);