[PATCH 08/19] perf tools: Add mem2node object

[Jiri Olsa <jolsa@kernel.org>]

Adding mem2node object to allow the easy lookup
of the node for the physical address.

It has following interface:

  int  mem2node__init(struct mem2node *map, struct perf_env *env);
  void mem2node__exit(struct mem2node *map);
  int  mem2node__node(struct mem2node *map, u64 addr);

The mem2node__init initialize object from the perf data
file MEM_TOPOLOGY feature data. Following calls to
mem2node__node will return node number for given
physical address. The mem2node__exit function frees
the object.

Link: http://lkml.kernel.org/n/tip-qq7sohu774wxq154n3my037z@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/Build      |   1 +
 tools/perf/util/mem2node.c | 129 +++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/mem2node.h |  19 +++++++
 3 files changed, 149 insertions(+)
 create mode 100644 tools/perf/util/mem2node.c
 create mode 100644 tools/perf/util/mem2node.h

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index ea0a452550b0..8052373bcd6a 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -106,6 +106,7 @@ libperf-y += units.o
 libperf-y += time-utils.o
 libperf-y += expr-bison.o
 libperf-y += branch.o
+libperf-y += mem2node.o
 
 libperf-$(CONFIG_LIBBPF) += bpf-loader.o
 libperf-$(CONFIG_BPF_PROLOGUE) += bpf-prologue.o
diff --git a/tools/perf/util/mem2node.c b/tools/perf/util/mem2node.c
new file mode 100644
index 000000000000..6da8ddbb1182
--- /dev/null
+++ b/tools/perf/util/mem2node.c
@@ -0,0 +1,129 @@
+#include <errno.h>
+#include <inttypes.h>
+#include <linux/bitmap.h>
+#include "mem2node.h"
+#include "util.h"
+
+struct entry {
+	struct rb_node	rb_node;
+	u64	start;
+	u64	end;
+	u64	node;
+};
+
+static void entry__insert(struct entry *entry, struct rb_root *root)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent = NULL;
+	struct entry *e;
+
+	while (*p != NULL) {
+		parent = *p;
+		e = rb_entry(parent, struct entry, rb_node);
+
+		if (entry->start < e->start)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+	}
+
+	rb_link_node(&entry->rb_node, parent, p);
+	rb_insert_color(&entry->rb_node, root);
+}
+
+int mem2node__init(struct mem2node *map, struct perf_env *env)
+{
+	struct memory_node *n, *nodes = &env->memory_nodes[0];
+	u64 bsize = env->memory_bsize;
+	struct entry *entry;
+	int i, j = 0, max = 0;
+
+	memset(map, 0x0, sizeof(*map));
+	map->root = RB_ROOT;
+
+	for (i = 0; i < env->nr_memory_nodes; i++) {
+		n = &nodes[i];
+		max += bitmap_weight(n->set, n->size);
+	}
+
+	entry = zalloc(sizeof(*entry) * max);
+	if (!entry)
+		return -ENOMEM;
+
+	for (i = 0; i < env->nr_memory_nodes; i++) {
+		u64 bit;
+
+		n = &nodes[i];
+
+		for (bit = 0; bit < n->size; bit++) {
+			u64 start;
+
+			if (!test_bit(bit, n->set))
+				continue;
+
+			start = bit * bsize;
+
+			/*
+			 * Merge nearby areas, we walk in order
+			 * through the bitmap, so no need to sort.
+			 */
+			if (j > 0) {
+				struct entry *prev = &entry[j - 1];
+
+				if ((prev->end == start) &&
+				    (prev->node == n->node)) {
+					prev->end += bsize;
+					continue;
+				}
+			}
+
+			entry[j].start = start;
+			entry[j].end   = start + bsize;
+			entry[j].node  = n->node;
+			RB_CLEAR_NODE(&entry[j].rb_node);
+			j++;
+		}
+	}
+
+	/* Cut unused entries, due to merging. */
+	entry = realloc(entry, sizeof(*entry) * j);
+	if (!entry)
+		return -ENOMEM;
+
+	for (i = 0; i < j; i++) {
+		pr_debug("mem2node %03" PRIu64 " [0x%016" PRIx64 "-0x%016" PRIx64 "]\n",
+			 entry[i].node, entry[i].start, entry[i].end);
+
+		entry__insert(&entry[i], &map->root);
+	}
+
+	map->entry = entry;
+	return 0;
+}
+
+void mem2node__exit(struct mem2node *map)
+{
+	zfree(&map->entry);
+}
+
+int mem2node__node(struct mem2node *map, u64 addr)
+{
+	struct rb_node **p, *parent = NULL;
+	struct entry *entry;
+
+	p = &map->root.rb_node;
+	while (*p != NULL) {
+		parent = *p;
+		entry = rb_entry(parent, struct entry, rb_node);
+		if (addr < entry->start)
+			p = &(*p)->rb_left;
+		else if (addr >= entry->end)
+			p = &(*p)->rb_right;
+		else
+			goto out;
+	}
+
+	entry = NULL;
+out:
+	return entry ? (int) entry->node : -1;
+}
diff --git a/tools/perf/util/mem2node.h b/tools/perf/util/mem2node.h
new file mode 100644
index 000000000000..e27333755a2c
--- /dev/null
+++ b/tools/perf/util/mem2node.h
@@ -0,0 +1,19 @@
+#ifndef __MEM2NODE_H
+#define __MEM2NODE_H
+
+#include <linux/rbtree.h>
+#include "env.h"
+
+struct entry;
+
+struct mem2node {
+	struct rb_root	 root;
+	struct entry	*entry;
+	int		 cnt;
+};
+
+int  mem2node__init(struct mem2node *map, struct perf_env *env);
+void mem2node__exit(struct mem2node *map);
+int  mem2node__node(struct mem2node *map, u64 addr);
+
+#endif /* __MEM2NODE_H */
-- 
2.13.6