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From:   Davidlohr Bueso <dave@stgolabs.net>
To:     acme@kernel.org
Cc:     mingo@kernel.org, linux-kernel@vger.kernel.org, dave@stgolabs.net,
        Davidlohr Bueso <dbueso@suse.de>
Subject: [PATCH 4/7] perf util: Use cached rbtree for rblists
Date:   Thu,  6 Dec 2018 11:18:16 -0800
Message-Id: <20181206191819.30182-5-dave@stgolabs.net>
In-Reply-To: <20181206191819.30182-1-dave@stgolabs.net>
References: <20181206191819.30182-1-dave@stgolabs.net>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

At the cost of an extra pointer, we can avoid the O(logN) cost
of finding the first element in the tree (smallest node), which
is something required for any of the strlist or intlist traversals
(XXX_for_each_entry()). There are a number of users in perf of
these (particularly strlists), including probes, and buildid.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
 tools/perf/util/intlist.h     |  2 +-
 tools/perf/util/metricgroup.c |  2 +-
 tools/perf/util/rb_resort.h   |  2 +-
 tools/perf/util/rblist.c      | 28 ++++++++++++++++++----------
 tools/perf/util/rblist.h      |  2 +-
 tools/perf/util/stat-shadow.c |  2 +-
 tools/perf/util/strlist.h     |  2 +-
 7 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/tools/perf/util/intlist.h b/tools/perf/util/intlist.h
index 85bab8735fa9..5c19ee001299 100644
--- a/tools/perf/util/intlist.h
+++ b/tools/perf/util/intlist.h
@@ -45,7 +45,7 @@ static inline unsigned int intlist__nr_entries(const struct intlist *ilist)
 /* For intlist iteration */
 static inline struct int_node *intlist__first(struct intlist *ilist)
 {
-	struct rb_node *rn = rb_first(&ilist->rblist.entries);
+	struct rb_node *rn = rb_first_cached(&ilist->rblist.entries);
 	return rn ? rb_entry(rn, struct int_node, rb_node) : NULL;
 }
 static inline struct int_node *intlist__next(struct int_node *in)
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index a28f9b5cc4ff..8529cbd3955b 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -352,7 +352,7 @@ void metricgroup__print(bool metrics, bool metricgroups, char *filter,
 	else if (metrics && !raw)
 		printf("\nMetrics:\n\n");
 
-	for (node = rb_first(&groups.entries); node; node = next) {
+	for (node = rb_first_cached(&groups.entries); node; node = next) {
 		struct mep *me = container_of(node, struct mep, nd);
 
 		if (metricgroups)
diff --git a/tools/perf/util/rb_resort.h b/tools/perf/util/rb_resort.h
index f272e181d3d6..376e86cb4c3c 100644
--- a/tools/perf/util/rb_resort.h
+++ b/tools/perf/util/rb_resort.h
@@ -140,7 +140,7 @@ struct __name##_sorted *__name = __name##_sorted__new
 
 /* For 'struct intlist' */
 #define DECLARE_RESORT_RB_INTLIST(__name, __ilist)				\
-	DECLARE_RESORT_RB(__name)(&__ilist->rblist.entries,			\
+	DECLARE_RESORT_RB(__name)(&__ilist->rblist.entries.rb_root,		\
 				  __ilist->rblist.nr_entries)
 
 /* For 'struct machine->threads' */
diff --git a/tools/perf/util/rblist.c b/tools/perf/util/rblist.c
index 0efc3258c648..11e07fab20dc 100644
--- a/tools/perf/util/rblist.c
+++ b/tools/perf/util/rblist.c
@@ -13,8 +13,9 @@
 
 int rblist__add_node(struct rblist *rblist, const void *new_entry)
 {
-	struct rb_node **p = &rblist->entries.rb_node;
+	struct rb_node **p = &rblist->entries.rb_root.rb_node;
 	struct rb_node *parent = NULL, *new_node;
+	bool leftmost = true;
 
 	while (*p != NULL) {
 		int rc;
@@ -24,8 +25,10 @@ int rblist__add_node(struct rblist *rblist, const void *new_entry)
 		rc = rblist->node_cmp(parent, new_entry);
 		if (rc > 0)
 			p = &(*p)->rb_left;
-		else if (rc < 0)
+		else if (rc < 0) {
 			p = &(*p)->rb_right;
+			leftmost = false;
+		}
 		else
 			return -EEXIST;
 	}
@@ -35,7 +38,7 @@ int rblist__add_node(struct rblist *rblist, const void *new_entry)
 		return -ENOMEM;
 
 	rb_link_node(new_node, parent, p);
-	rb_insert_color(new_node, &rblist->entries);
+	rb_insert_color_cached(new_node, &rblist->entries, leftmost);
 	++rblist->nr_entries;
 
 	return 0;
@@ -43,7 +46,7 @@ int rblist__add_node(struct rblist *rblist, const void *new_entry)
 
 void rblist__remove_node(struct rblist *rblist, struct rb_node *rb_node)
 {
-	rb_erase(rb_node, &rblist->entries);
+	rb_erase_cached(rb_node, &rblist->entries);
 	--rblist->nr_entries;
 	rblist->node_delete(rblist, rb_node);
 }
@@ -52,8 +55,9 @@ static struct rb_node *__rblist__findnew(struct rblist *rblist,
 					 const void *entry,
 					 bool create)
 {
-	struct rb_node **p = &rblist->entries.rb_node;
+	struct rb_node **p = &rblist->entries.rb_root.rb_node;
 	struct rb_node *parent = NULL, *new_node = NULL;
+	bool leftmost = true;
 
 	while (*p != NULL) {
 		int rc;
@@ -63,8 +67,10 @@ static struct rb_node *__rblist__findnew(struct rblist *rblist,
 		rc = rblist->node_cmp(parent, entry);
 		if (rc > 0)
 			p = &(*p)->rb_left;
-		else if (rc < 0)
+		else if (rc < 0) {
 			p = &(*p)->rb_right;
+			leftmost = false;
+		}
 		else
 			return parent;
 	}
@@ -73,7 +79,8 @@ static struct rb_node *__rblist__findnew(struct rblist *rblist,
 		new_node = rblist->node_new(rblist, entry);
 		if (new_node) {
 			rb_link_node(new_node, parent, p);
-			rb_insert_color(new_node, &rblist->entries);
+			rb_insert_color_cached(new_node,
+					       &rblist->entries, leftmost);
 			++rblist->nr_entries;
 		}
 	}
@@ -94,7 +101,7 @@ struct rb_node *rblist__findnew(struct rblist *rblist, const void *entry)
 void rblist__init(struct rblist *rblist)
 {
 	if (rblist != NULL) {
-		rblist->entries	 = RB_ROOT;
+		rblist->entries	 = RB_ROOT_CACHED;
 		rblist->nr_entries = 0;
 	}
 
@@ -103,7 +110,7 @@ void rblist__init(struct rblist *rblist)
 
 void rblist__exit(struct rblist *rblist)
 {
-	struct rb_node *pos, *next = rb_first(&rblist->entries);
+	struct rb_node *pos, *next = rb_first_cached(&rblist->entries);
 
 	while (next) {
 		pos = next;
@@ -124,7 +131,8 @@ struct rb_node *rblist__entry(const struct rblist *rblist, unsigned int idx)
 {
 	struct rb_node *node;
 
-	for (node = rb_first(&rblist->entries); node; node = rb_next(node)) {
+	for (node = rb_first_cached(&rblist->entries); node;
+	     node = rb_next(node)) {
 		if (!idx--)
 			return node;
 	}
diff --git a/tools/perf/util/rblist.h b/tools/perf/util/rblist.h
index 76df15c27f5f..14b232a4d0b6 100644
--- a/tools/perf/util/rblist.h
+++ b/tools/perf/util/rblist.h
@@ -20,7 +20,7 @@
  */
 
 struct rblist {
-	struct rb_root entries;
+	struct rb_root_cached entries;
 	unsigned int   nr_entries;
 
 	int (*node_cmp)(struct rb_node *rbn, const void *entry);
diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index f0a8cec55c47..463160a5494c 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -168,7 +168,7 @@ static void reset_stat(struct runtime_stat *st)
 	struct rb_node *pos, *next;
 
 	rblist = &st->value_list;
-	next = rb_first(&rblist->entries);
+	next = rb_first_cached(&rblist->entries);
 	while (next) {
 		pos = next;
 		next = rb_next(pos);
diff --git a/tools/perf/util/strlist.h b/tools/perf/util/strlist.h
index d58f1e08b170..7e82c71dcc42 100644
--- a/tools/perf/util/strlist.h
+++ b/tools/perf/util/strlist.h
@@ -57,7 +57,7 @@ static inline unsigned int strlist__nr_entries(const struct strlist *slist)
 /* For strlist iteration */
 static inline struct str_node *strlist__first(struct strlist *slist)
 {
-	struct rb_node *rn = rb_first(&slist->rblist.entries);
+	struct rb_node *rn = rb_first_cached(&slist->rblist.entries);
 	return rn ? rb_entry(rn, struct str_node, rb_node) : NULL;
 }
 static inline struct str_node *strlist__next(struct str_node *sn)
-- 
2.16.4