[RFC v1 02/11] vfs: introduce one rb tree - hot_inode_tree

zwu.kernel
2012-09-17T07:19:14Z

Adds hot_inode_tree struct to keep track of
frequently accessed files, and be keyed by {inode, offset}.
Trees contain hot_inode_items representing those files
and ranges.
Having these trees means that vfs can quickly determine the
temperature of some data by doing some calculations on the
hot_freq_data struct that hangs off of the tree item.

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
---
fs/Makefile | 3 ++-
fs/hot_rb.c | 30 ++++++++++++++++++++++++++++++
fs/hot_rb.h | 21 +++++++++++++++++++++
include/linux/hot_track.h | 9 +++++++++
4 files changed, 62 insertions(+), 1 deletions(-)
create mode 100644 fs/hot_rb.c
create mode 100644 fs/hot_rb.h

diff --git a/fs/Makefile b/fs/Makefile
index 2fb9779..d3bc906 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -11,7 +11,8 @@ obj-y := open.o read_write.o file_table.o super.o \
attr.o bad_inode.o file.o filesystems.o namespace.o \
seq_file.o xattr.o libfs.o fs-writeback.o \
pnode.o drop_caches.o splice.o sync.o utimes.o \
- stack.o fs_struct.o statfs.o
+ stack.o fs_struct.o statfs.o \
+ hot_rb.o

ifeq ($(CONFIG_BLOCK),y)
obj-y += buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
diff --git a/fs/hot_rb.c b/fs/hot_rb.c
new file mode 100644
index 0000000..726d1c5
--- /dev/null
+++ b/fs/hot_rb.c
@@ -0,0 +1,30 @@
+/*
+ * fs/hot_rb.c
+ *
+ * Copyright (C) 2012 IBM Corp. All rights reserved.
+ * Written by Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
+ * Ben Chociej <bchociej@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/hardirq.h>
+#include <linux/blkdev.h>
+#include "hot_rb.h"
+#include "hot_hash.h"
+
+/*
+ * Initialize the inode tree. Should be called for each new inode
+ * access or other user of the hot_inode interface.
+ */
+void hot_rb_inode_tree_init(struct hot_inode_tree *tree)
+{
+ tree->map = RB_ROOT;
+ rwlock_init(&tree->lock);
+}
diff --git a/fs/hot_rb.h b/fs/hot_rb.h
new file mode 100644
index 0000000..895c61c
--- /dev/null
+++ b/fs/hot_rb.h
@@ -0,0 +1,21 @@
+/*
+ * fs/hot_rb.h
+ *
+ * Copyright (C) 2012 IBM Corp. All rights reserved.
+ * Written by Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
+ * Ben Chociej <bchociej@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ */
+
+#ifndef __HOT_MAP__
+#define __HOT_MAP__
+
+#include <linux/rbtree.h>
+#include <linux/hot_track.h>
+
+void hot_rb_inode_tree_init(struct hot_inode_tree *tree);
+
+#endif /* __HOT_MAP__ */
diff --git a/include/linux/hot_track.h b/include/linux/hot_track.h
index 5716b93..fa2aeb6 100644
--- a/include/linux/hot_track.h
+++ b/include/linux/hot_track.h
@@ -20,7 +20,16 @@
#include <linux/rbtree.h>
#include <linux/kref.h>

+/* A tree that sits on the hot_info */
+struct hot_inode_tree {
+ struct rb_root map;
+ rwlock_t lock;
+};
+
struct hot_info {
+
+ /* red-black tree that keeps track of fs-wide hot data */
+ struct hot_inode_tree hot_inode_tree;
};

#endif /* _LINUX_HOTTRACK_H */
--
1.7.6.5