perf pmu: Special case uncore_ prefix

Special case uncore_ prefix in PMU match, to allow for shorter event
uncore specifications.

Before:

perf stat -a -e uncore_cbox/event=0x35,umask=0x1,filter_opc=0x19C/ sleep 1

After

perf stat -a -e cbox/event=0x35,umask=0x1,filter_opc=0x19C/ sleep 1

Committer tests:

# perf list uncore

List of pre-defined events (to be used in -e):

uncore_cbox_0/clockticks/ [Kernel PMU event]
uncore_cbox_1/clockticks/ [Kernel PMU event]
uncore_imc/data_reads/ [Kernel PMU event]
uncore_imc/data_writes/ [Kernel PMU event]

# perf stat -a -e cbox_0/clockticks/ sleep 1

Performance counter stats for 'system wide':

281,474,976,653,084 cbox_0/clockticks/

1.000870129 seconds time elapsed

#

Signed-off-by: Andi Kleen <[e-mail]>
Acked-by: Jiri Olsa <[e-mail]>
Tested-by: Arnaldo Carvalho de Melo <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/parse-events.y

···
 		while ((pmu = perf_pmu__scan(pmu)) != NULL) {
 			char *name = pmu->name;
 
+			if (!strncmp(name, "uncore_", 7) &&
+			    strncmp($1, "uncore_", 7))
+				name += 7;
 			if (!strncmp($1, name, strlen($1))) {
 				if (parse_events_copy_term_list(orig_terms, &terms))
 					YYABORT;