perf list: Allow filtering list of events

The man page has the details, here are some examples:

[root@emilia ~]# perf list *fault*  *:*wait*

List of pre-defined events (to be used in -e):
  page-faults OR faults                      [Software event]
  minor-faults                               [Software event]
  major-faults                               [Software event]
  alignment-faults                           [Software event]
  emulation-faults                           [Software event]

  radeon:radeon_fence_wait_begin             [Tracepoint event]
  radeon:radeon_fence_wait_end               [Tracepoint event]
  writeback:wbc_writeback_wait               [Tracepoint event]
  writeback:wbc_balance_dirty_wait           [Tracepoint event]
  writeback:writeback_congestion_wait        [Tracepoint event]
  writeback:writeback_wait_iff_congested     [Tracepoint event]
  sched:sched_wait_task                      [Tracepoint event]
  sched:sched_process_wait                   [Tracepoint event]
  sched:sched_stat_wait                      [Tracepoint event]
  sched:sched_stat_iowait                    [Tracepoint event]
  syscalls:sys_enter_epoll_wait              [Tracepoint event]
  syscalls:sys_exit_epoll_wait               [Tracepoint event]
  syscalls:sys_enter_epoll_pwait             [Tracepoint event]
  syscalls:sys_exit_epoll_pwait              [Tracepoint event]
  syscalls:sys_enter_rt_sigtimedwait         [Tracepoint event]
  syscalls:sys_exit_rt_sigtimedwait          [Tracepoint event]
  syscalls:sys_enter_waitid                  [Tracepoint event]
  syscalls:sys_exit_waitid                   [Tracepoint event]
  syscalls:sys_enter_wait4                   [Tracepoint event]
  syscalls:sys_exit_wait4                    [Tracepoint event]
  syscalls:sys_enter_waitpid                 [Tracepoint event]
  syscalls:sys_exit_waitpid                  [Tracepoint event]
[root@emilia ~]#

Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-list.c b/tools/perf/builtin-list.c
index d88c696..6313b6e 100644
--- a/tools/perf/builtin-list.c
+++ b/tools/perf/builtin-list.c
@@ -5,6 +5,7 @@
  *
  * Copyright (C) 2009, Thomas Gleixner <tglx@linutronix.de>
  * Copyright (C) 2008-2009, Red Hat Inc, Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
  */
 #include "builtin.h"
 
@@ -13,9 +14,47 @@
 #include "util/parse-events.h"
 #include "util/cache.h"
 
-int cmd_list(int argc __used, const char **argv __used, const char *prefix __used)
+int cmd_list(int argc, const char **argv, const char *prefix __used)
 {
 	setup_pager();
-	print_events();
+
+	if (argc == 1)
+		print_events(NULL);
+	else {
+		int i;
+
+		for (i = 1; i < argc; ++i) {
+			if (i > 1)
+				putchar('\n');
+			if (strncmp(argv[i], "tracepoint", 10) == 0)
+				print_tracepoint_events(NULL, NULL);
+			else if (strcmp(argv[i], "hw") == 0 ||
+				 strcmp(argv[i], "hardware") == 0)
+				print_events_type(PERF_TYPE_HARDWARE);
+			else if (strcmp(argv[i], "sw") == 0 ||
+				 strcmp(argv[i], "software") == 0)
+				print_events_type(PERF_TYPE_SOFTWARE);
+			else if (strcmp(argv[i], "cache") == 0 ||
+				 strcmp(argv[i], "hwcache") == 0)
+				print_hwcache_events(NULL);
+			else {
+				char *sep = strchr(argv[i], ':'), *s;
+				int sep_idx;
+
+				if (sep == NULL) {
+					print_events(argv[i]);
+					continue;
+				}
+				sep_idx = sep - argv[i];
+				s = strdup(argv[i]);
+				if (s == NULL)
+					return -1;
+
+				s[sep_idx] = '\0';
+				print_tracepoint_events(s, s + sep_idx + 1);
+				free(s);
+			}
+		}
+	}
 	return 0;
 }