From: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
Adds two map arrays which contains
a lot of list and is used to efficiently
look up the data temperature of a file or its
ranges.
In each list of map arrays, the array node
will keep track of temperature info.
Signed-off-by: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
---
fs/hot_tracking.c | 55 ++++++++++++++++++++++++++++++++++++++++++
include/linux/hot_tracking.h | 16 ++++++++++++
2 files changed, 71 insertions(+), 0 deletions(-)
diff --git a/fs/hot_tracking.c b/fs/hot_tracking.c
index 201598b..b5568bc 100644
--- a/fs/hot_tracking.c
+++ b/fs/hot_tracking.c
@@ -60,6 +60,7 @@ static void hot_range_item_init(struct hot_range_item *hr, u32 start,
hr->hot_inode = he;
kref_init(&hr->hot_range.refs);
spin_lock_init(&hr->hot_range.lock);
+ INIT_LIST_HEAD(&hr->hot_range.n_list);
hr->hot_range.hot_freq_data.avg_delta_reads = (u64) -1;
hr->hot_range.hot_freq_data.avg_delta_writes = (u64) -1;
hr->hot_range.hot_freq_data.flags = FREQ_DATA_TYPE_RANGE;
@@ -91,6 +92,13 @@ static void hot_range_item_free(struct kref *kref)
struct hot_range_item *hr = container_of(comm_item,
struct hot_range_item, hot_range);
+ spin_lock(&hr->hot_range.lock);
+ if (!list_empty(&hr->hot_range.n_list)) {
+ list_del_init(&hr->hot_range.n_list);
+ hot_root->hot_map_nr--;
+ }
+ spin_unlock(&hr->hot_range.lock);
+
radix_tree_delete(&hr->hot_inode->hot_range_tree, hr->start);
kmem_cache_free(hot_range_item_cachep, hr);
}
@@ -135,6 +143,13 @@ static void hot_inode_item_free(struct kref *kref)
struct hot_inode_item *he = container_of(comm_item,
struct hot_inode_item, hot_inode);
+ spin_lock(&he->hot_inode.lock);
+ if (!list_empty(&he->hot_inode.n_list)) {
+ list_del_init(&he->hot_inode.n_list);
+ hot_root->hot_map_nr--;
+ }
+ spin_unlock(&he->hot_inode.lock);
+
hot_range_tree_free(he);
radix_tree_delete(he->hot_inode_tree, he->i_ino);
kmem_cache_free(hot_inode_item_cachep, he);
@@ -317,6 +332,44 @@ static void hot_freq_data_update(struct hot_freq_data *freq_data, bool write)
}
/*
+ * Initialize inode and range map arrays.
+ */
+static void hot_map_array_init(struct hot_info *root)
+{
+ int i;
+ for (i = 0; i < HEAT_MAP_SIZE; i++) {
+ INIT_LIST_HEAD(&root->heat_inode_map[i].node_list);
+ INIT_LIST_HEAD(&root->heat_range_map[i].node_list);
+ root->heat_inode_map[i].temp = i;
+ root->heat_range_map[i].temp = i;
+ }
+}
+
+static void hot_map_list_free(struct list_head *node_list,
+ struct hot_info *root)
+{
+ struct list_head *pos, *next;
+ struct hot_comm_item *node;
+
+ list_for_each_safe(pos, next, node_list) {
+ node = list_entry(pos, struct hot_comm_item, n_list);
+ list_del_init(&node->n_list);
+ root->hot_map_nr--;
+ }
+
+}
+
+/* Free inode and range map arrays */
+static void hot_map_array_exit(struct hot_info *root)
+{
+ int i;
+ for (i = 0; i < HEAT_MAP_SIZE; i++) {
+ hot_map_list_free(&root->heat_inode_map[i].node_list, root);
+ hot_map_list_free(&root->heat_range_map[i].node_list, root);
+ }
+}
+
+/*
* Initialize kmem cache for hot_inode_item and hot_range_item.
*/
void __init hot_cache_init(void)
@@ -406,6 +459,7 @@ int hot_track_init(struct super_block *sb)
sb->s_hot_root = hot_root = root;
hot_inode_tree_init(root);
+ hot_map_array_init(root);
printk(KERN_INFO "VFS: Turning on hot data tracking\n");
@@ -417,6 +471,7 @@ void hot_track_exit(struct super_block *sb)
{
struct hot_info *root = sb->s_hot_root;
+ hot_map_array_exit(root);
hot_inode_tree_exit(root);
kfree(root);
}
diff --git a/include/linux/hot_tracking.h b/include/linux/hot_tracking.h
index de68f66..0ce2ef8 100644
--- a/include/linux/hot_tracking.h
+++ b/include/linux/hot_tracking.h
@@ -20,6 +20,9 @@
#include <linux/kref.h>
#include <linux/fs.h>
+#define HEAT_MAP_BITS 8
+#define HEAT_MAP_SIZE (1 << HEAT_MAP_BITS)
+
/*
* A frequency data struct holds values that are used to
* determine temperature of files and file ranges. These structs
@@ -36,11 +39,18 @@ struct hot_freq_data {
u32 last_temp;
};
+/* List heads in hot map array */
+struct hot_map_head {
+ struct list_head node_list;
+ u8 temp;
+};
+
/* The common info for both following structures */
struct hot_comm_item {
struct hot_freq_data hot_freq_data; /* frequency data */
spinlock_t lock; /* protects object data */
struct kref refs; /* prevents kfree */
+ struct list_head n_list; /* list node index */
};
/* An item representing an inode and its access frequency */
@@ -66,6 +76,12 @@ struct hot_range_item {
struct hot_info {
struct radix_tree_root hot_inode_tree;
spinlock_t lock; /*protect inode tree */
+
+ /* map of inode temperature */
+ struct hot_map_head heat_inode_map[HEAT_MAP_SIZE];
+ /* map of range temperature */
+ struct hot_map_head heat_range_map[HEAT_MAP_SIZE];
+ unsigned int hot_map_nr;
};
void __init hot_cache_init(void);
--
1.7.6.5
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