perf probe: Remove caches when --cache is given

'perf probe --del' removes caches when '--cache' is given.  Note that
the delete pattern is not the same as for normal events.

If you cached probes with event name, --del "eventname" works as
expected. However, if you skipped it, the cached probes doesn't have
actual event name. In that case --del "probe-desc" is required (wildcard
is acceptable).  For example a cache entry has the probe-desc "vfs_read
$params", you can remove it with --del 'vfs_read*'.

  -----
  # perf probe --cache --list
  /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
  vfs_read $params
  /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
  getaddrinfo $params

  # perf probe --cache --del vfs_read\*
  Removed cached event: probe:vfs_read

  # perf probe --cache --list
  /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
  /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
  getaddrinfo $params
  -----

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146736021651.27797.10250879847070772920.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-probe.txt

@@ -116,6 +116,7 @@ OPTIONS
 	(With --add) Cache the probes. Any events which successfully added
 	are also stored in the cache file.
 	(With --list) Show cached probes.
+	(With --del) Remove cached probes.
 
 --max-probes=NUM::
 	Set the maximum number of probe points for an event. Default is 128.

tools/perf/builtin-probe.c

@@ -363,6 +363,32 @@ out_cleanup:
 	return ret;
 }
 
+static int del_perf_probe_caches(struct strfilter *filter)
+{
+	struct probe_cache *cache;
+	struct strlist *bidlist;
+	struct str_node *nd;
+	int ret;
+
+	bidlist = build_id_cache__list_all();
+	if (!bidlist) {
+		ret = -errno;
+		pr_debug("Failed to get buildids: %d\n", ret);
+		return ret ?: -ENOMEM;
+	}
+
+	strlist__for_each_entry(nd, bidlist) {
+		cache = probe_cache__new(nd->s);
+		if (!cache)
+			continue;
+		if (probe_cache__filter_purge(cache, filter) < 0 ||
+		    probe_cache__commit(cache) < 0)
+			pr_warning("Failed to remove entries for %s\n", nd->s);
+		probe_cache__delete(cache);
+	}
+	return 0;
+}
+
 static int perf_del_probe_events(struct strfilter *filter)
 {
 	int ret, ret2, ufd = -1, kfd = -1;
@@ -375,6 +401,9 @@ static int perf_del_probe_events(struct strfilter *filter)
 
 	pr_debug("Delete filter: \'%s\'\n", str);
 
+	if (probe_conf.cache)
+		return del_perf_probe_caches(filter);
+
 	/* Get current event names */
 	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
 	if (ret < 0)

tools/perf/util/probe-file.c

@@ -684,20 +684,40 @@ out:
 	return ret;
 }
 
+static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
+				       struct strfilter *filter)
+{
+	char buf[128], *ptr = entry->spev;
+
+	if (entry->pev.event) {
+		snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
+		ptr = buf;
+	}
+	return strfilter__compare(filter, ptr);
+}
+
+int probe_cache__filter_purge(struct probe_cache *pcache,
+			      struct strfilter *filter)
+{
+	struct probe_cache_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &pcache->entries, node) {
+		if (probe_cache_entry__compare(entry, filter)) {
+			pr_info("Removed cached event: %s\n", entry->spev);
+			list_del_init(&entry->node);
+			probe_cache_entry__delete(entry);
+		}
+	}
+	return 0;
+}
+
 static int probe_cache__show_entries(struct probe_cache *pcache,
 				     struct strfilter *filter)
 {
 	struct probe_cache_entry *entry;
-	char buf[128], *ptr;
 
 	list_for_each_entry(entry, &pcache->entries, node) {
-		if (entry->pev.event) {
-			ptr = buf;
-			snprintf(buf, 128, "%s:%s",
-				 entry->pev.group, entry->pev.event);
-		} else
-			ptr = entry->spev;
-		if (strfilter__compare(filter, ptr))
+		if (probe_cache_entry__compare(entry, filter))
 			printf("%s\n", entry->spev);
 	}
 	return 0;

tools/perf/util/probe-file.h

@@ -38,6 +38,8 @@ int probe_cache__add_entry(struct probe_cache *pcache,
 int probe_cache__commit(struct probe_cache *pcache);
 void probe_cache__purge(struct probe_cache *pcache);
 void probe_cache__delete(struct probe_cache *pcache);
+int probe_cache__filter_purge(struct probe_cache *pcache,
+			      struct strfilter *filter);
 struct probe_cache_entry *probe_cache__find(struct probe_cache *pcache,
 					    struct perf_probe_event *pev);
 struct probe_cache_entry *probe_cache__find_by_name(struct probe_cache *pcache,