[PATCH RFC 5/6] perf auxtrace: Add auxtrace_cache__remove()

[Adrian Hunter]

Add auxtrace_cache__remove(). Intel PT uses an auxtrace_cache to store the
results of code-walking, so that the same block of instructions does not
have to be decoded repeatedly. However, when there are text poke events,
the associated cache entries need to be removed.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 tools/perf/util/auxtrace.c | 28 ++++++++++++++++++++++++++++
 tools/perf/util/auxtrace.h |  1 +
 2 files changed, 29 insertions(+)

diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index 8470dfe9fe97..c555c3ccd79d 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -1457,6 +1457,34 @@ int auxtrace_cache__add(struct auxtrace_cache *c, u32 key,
 	return 0;
 }
 
+static struct auxtrace_cache_entry *auxtrace_cache__rm(struct auxtrace_cache *c,
+						       u32 key)
+{
+	struct auxtrace_cache_entry *entry;
+	struct hlist_head *hlist;
+	struct hlist_node *n;
+
+	if (!c)
+		return NULL;
+
+	hlist = &c->hashtable[hash_32(key, c->bits)];
+	hlist_for_each_entry_safe(entry, n, hlist, hash) {
+		if (entry->key == key) {
+			hlist_del(&entry->hash);
+			return entry;
+		}
+	}
+
+	return NULL;
+}
+
+void auxtrace_cache__remove(struct auxtrace_cache *c, u32 key)
+{
+	struct auxtrace_cache_entry *entry = auxtrace_cache__rm(c, key);
+
+	auxtrace_cache__free_entry(c, entry);
+}
+
 void *auxtrace_cache__lookup(struct auxtrace_cache *c, u32 key)
 {
 	struct auxtrace_cache_entry *entry;
diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
index f201f36bc35f..3f4aa5427d76 100644
--- a/tools/perf/util/auxtrace.h
+++ b/tools/perf/util/auxtrace.h
@@ -489,6 +489,7 @@ void *auxtrace_cache__alloc_entry(struct auxtrace_cache *c);
 void auxtrace_cache__free_entry(struct auxtrace_cache *c, void *entry);
 int auxtrace_cache__add(struct auxtrace_cache *c, u32 key,
 			struct auxtrace_cache_entry *entry);
+void auxtrace_cache__remove(struct auxtrace_cache *c, u32 key);
 void *auxtrace_cache__lookup(struct auxtrace_cache *c, u32 key);
 
 struct auxtrace_record *auxtrace_record__init(struct evlist *evlist,
-- 
2.17.1