perf list: Do event name substring search as last resort when no events found

Before:

# perf list _alloc_ | head -10
#

After:

# perf list _alloc_ | head -10
ext4:ext4_alloc_da_blocks [Tracepoint event]
ext4:ext4_get_implied_cluster_alloc_exit [Tracepoint event]
kmem:kmem_cache_alloc_node [Tracepoint event]
kmem:mm_page_alloc_extfrag [Tracepoint event]
kmem:mm_page_alloc_zone_locked [Tracepoint event]
xen:xen_mmu_alloc_ptpage [Tracepoint event]
#

And it works for all types of events:

# perf list br

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

branch-instructions OR branches [Hardware event]
branch-misses [Hardware event]

branch-load-misses [Hardware cache event]
branch-loads [Hardware cache event]

branch-instructions OR cpu/branch-instructions/ [Kernel PMU event]
branch-misses OR cpu/branch-misses/ [Kernel PMU event]

filelock:break_lease_block [Tracepoint event]
filelock:break_lease_noblock [Tracepoint event]
filelock:break_lease_unblock [Tracepoint event]
syscalls:sys_enter_brk [Tracepoint event]
syscalls:sys_exit_brk [Tracepoint event]

#

Suggested-by: Ingo Molnar <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/Documentation/perf-list.txt

···
 . If none of the above is matched, it will apply the supplied glob to all
   events, printing the ones that match.
 
+. As a last resort, it will do a substring search in all event names.
+
 One or more types can be used at the same time, listing the events for the
 types specified.
 

tools/perf/builtin-list.c

···
 	}
 
 	for (i = 0; i < argc; ++i) {
+		char *sep, *s;
+
 		if (strcmp(argv[i], "tracepoint") == 0)
 			print_tracepoint_events(NULL, NULL, raw_dump);
 		else if (strcmp(argv[i], "hw") == 0 ||
···
 			print_hwcache_events(NULL, raw_dump);
 		else if (strcmp(argv[i], "pmu") == 0)
 			print_pmu_events(NULL, raw_dump);
-		else {
-			char *sep = strchr(argv[i], ':'), *s;
+		else if ((sep = strchr(argv[i], ':')) != NULL) {
 			int sep_idx;
 
 			if (sep == NULL) {
···
 
 			s[sep_idx] = '\0';
 			print_tracepoint_events(s, s + sep_idx + 1, raw_dump);
+			free(s);
+		} else {
+			if (asprintf(&s, "*%s*", argv[i]) < 0) {
+				printf("Critical: Not enough memory! Trying to continue...\n");
+				continue;
+			}
+			print_symbol_events(s, PERF_TYPE_HARDWARE,
+					    event_symbols_hw, PERF_COUNT_HW_MAX, raw_dump);
+			print_symbol_events(s, PERF_TYPE_SOFTWARE,
+					    event_symbols_sw, PERF_COUNT_SW_MAX, raw_dump);
+			print_hwcache_events(s, raw_dump);
+			print_pmu_events(s, raw_dump);
+			print_tracepoint_events(NULL, s, raw_dump);
 			free(s);
 		}
 	}