From: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
Add a /sys/kernel/debug/hot_track/<device_name>/ directory for each
volume that contains two files. The first, `inode_stats', contains the
heat information for inodes that have been brought into the hot data map
structures. The second, `range_stats', contains similar information for
subfile ranges.
Signed-off-by: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
---
fs/hot_tracking.c | 513 +++++++++++++++++++++++++++++++++++++++++-
fs/hot_tracking.h | 5 +
include/linux/hot_tracking.h | 1 +
3 files changed, 517 insertions(+), 2 deletions(-)
diff --git a/fs/hot_tracking.c b/fs/hot_tracking.c
index a59521c..94fe029 100644
--- a/fs/hot_tracking.c
+++ b/fs/hot_tracking.c
@@ -21,9 +21,12 @@
#include <linux/blkdev.h>
#include <linux/types.h>
#include <linux/list_sort.h>
+#include <linux/debugfs.h>
#include <linux/limits.h>
#include "hot_tracking.h"
+static struct dentry *hot_debugfs_root;
+
/* kmem_cache pointers for slab caches */
static struct kmem_cache *hot_inode_item_cachep __read_mostly;
static struct kmem_cache *hot_range_item_cachep __read_mostly;
@@ -218,8 +221,8 @@ struct hot_inode_item
else if (ino > entry->i_ino)
p = &(*p)->rb_right;
else {
- spin_unlock(&root->lock);
kref_get(&entry->hot_inode.refs);
+ spin_unlock(&root->lock);
return entry;
}
}
@@ -269,8 +272,8 @@ static struct hot_range_item
else if (start > hot_range_end(entry))
p = &(*p)->rb_right;
else {
- spin_unlock(&he->lock);
kref_get(&entry->hot_range.refs);
+ spin_unlock(&he->lock);
return entry;
}
}
@@ -617,6 +620,499 @@ static void hot_update_worker(struct work_struct *work)
msecs_to_jiffies(HEAT_UPDATE_DELAY * MSEC_PER_SEC));
}
+static void *hot_range_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct hot_info *root = seq->private;
+ struct rb_node *node, *node2;
+ struct hot_comm_item *ci;
+ struct hot_inode_item *he;
+ struct hot_range_item *hr;
+ loff_t l = *pos;
+
+ spin_lock(&root->lock);
+ node = rb_first(&root->hot_inode_tree.map);
+ while (node) {
+ ci = rb_entry(node, struct hot_comm_item, rb_node);
+ he = container_of(ci, struct hot_inode_item, hot_inode);
+ spin_lock(&he->lock);
+ node2 = rb_first(&he->hot_range_tree.map);
+ while (node2) {
+ if (!l--) {
+ ci = rb_entry(node2,
+ struct hot_comm_item, rb_node);
+ hr = container_of(ci,
+ struct hot_range_item, hot_range);
+ kref_get(&hr->hot_range.refs);
+ spin_unlock(&he->lock);
+ spin_unlock(&root->lock);
+ return hr;
+ }
+ node2 = rb_next(node2);
+ }
+ node = rb_next(node);
+ spin_unlock(&he->lock);
+ }
+ spin_unlock(&root->lock);
+ return NULL;
+}
+
+static void *hot_range_seq_next(struct seq_file *seq,
+ void *v, loff_t *pos)
+{
+ struct rb_node *node, *node2;
+ struct hot_comm_item *ci;
+ struct hot_inode_item *he;
+ struct hot_range_item *hr_next = NULL, *hr = v;
+
+ spin_lock(&hr->hot_range.lock);
+ (*pos)++;
+ node2 = rb_next(&hr->hot_range.rb_node);
+ if (node2)
+ goto next;
+
+ node = rb_next(&hr->hot_inode->hot_inode.rb_node);
+ if (node) {
+ ci = rb_entry(node, struct hot_comm_item, rb_node);
+ he = container_of(ci, struct hot_inode_item, hot_inode);
+ node2 = rb_first(&he->hot_range_tree.map);
+ if (node2) {
+next:
+ ci = rb_entry(node2,
+ struct hot_comm_item, rb_node);
+ hr_next = container_of(ci,
+ struct hot_range_item, hot_range);
+ kref_get(&hr_next->hot_range.refs);
+ }
+ }
+ spin_unlock(&hr->hot_range.lock);
+
+ hot_range_item_put(hr);
+ return hr_next;
+}
+
+static void hot_range_seq_stop(struct seq_file *seq, void *v)
+{
+ struct hot_range_item *hr = v;
+
+ if (hr)
+ hot_range_item_put(hr);
+}
+
+static int hot_range_seq_show(struct seq_file *seq, void *v)
+{
+ struct hot_range_item *hr = v;
+ struct hot_inode_item *he = hr->hot_inode;
+ struct hot_freq_data *freq_data = &hr->hot_range.hot_freq_data;
+ struct hot_info *root = container_of(he->hot_inode_tree,
+ struct hot_info, hot_inode_tree);
+ loff_t start = hr->start * hot_raw_shift(1,
+ root->hot_type->range_bits, true);
+
+ /* Always lock hot_inode_item first */
+ spin_lock(&he->hot_inode.lock);
+ spin_lock(&hr->hot_range.lock);
+ seq_printf(seq, "inode %llu, range " \
+ "%llu+%llu, reads %u, writes %u, temp %u\n",
+ he->i_ino, (unsigned long long)start,
+ (unsigned long long)hr->len,
+ freq_data->nr_reads,
+ freq_data->nr_writes,
+ (u8)hot_raw_shift((u64)freq_data->last_temp,
+ (32 - HEAT_MAP_BITS), false));
+ spin_unlock(&hr->hot_range.lock);
+ spin_unlock(&he->hot_inode.lock);
+
+ return 0;
+}
+
+static void *hot_inode_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct hot_info *root = seq->private;
+ struct rb_node *node;
+ struct hot_comm_item *ci;
+ struct hot_inode_item *he = NULL;
+ loff_t l = *pos;
+
+ spin_lock(&root->lock);
+ node = rb_first(&root->hot_inode_tree.map);
+ while (node) {
+ if (!l--) {
+ ci = rb_entry(node, struct hot_comm_item, rb_node);
+ he = container_of(ci,
+ struct hot_inode_item, hot_inode);
+ kref_get(&he->hot_inode.refs);
+ break;
+ }
+ node = rb_next(node);
+ }
+ spin_unlock(&root->lock);
+
+ return he;
+}
+
+static void *hot_inode_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct hot_inode_item *he_next = NULL, *he = v;
+ struct rb_node *node;
+ struct hot_comm_item *ci;
+
+ spin_lock(&he->hot_inode.lock);
+ (*pos)++;
+ node = rb_next(&he->hot_inode.rb_node);
+ if (node) {
+ ci = rb_entry(node, struct hot_comm_item, rb_node);
+ he_next = container_of(ci,
+ struct hot_inode_item, hot_inode);
+ kref_get(&he_next->hot_inode.refs);
+ }
+ spin_unlock(&he->hot_inode.lock);
+
+ hot_inode_item_put(he);
+
+ return he_next;
+}
+
+static void hot_inode_seq_stop(struct seq_file *seq, void *v)
+{
+ struct hot_inode_item *he = v;
+
+ if (he)
+ hot_inode_item_put(he);
+}
+
+static int hot_inode_seq_show(struct seq_file *seq, void *v)
+{
+ struct hot_inode_item *he = v;
+ struct hot_freq_data *freq_data = &he->hot_inode.hot_freq_data;
+
+ spin_lock(&he->hot_inode.lock);
+ seq_printf(seq, "inode %llu, reads %u, writes %u, temp %d\n",
+ he->i_ino,
+ freq_data->nr_reads,
+ freq_data->nr_writes,
+ (u8)hot_raw_shift((u64)freq_data->last_temp,
+ (32 - HEAT_MAP_BITS), false));
+ spin_unlock(&he->hot_inode.lock);
+
+ return 0;
+}
+
+static void *hot_spot_range_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct hot_info *root = seq->private;
+ struct hot_range_item *hr;
+ struct hot_comm_item *comm_item;
+ struct list_head *n_list;
+ int i;
+
+ for (i = HEAT_MAP_SIZE - 1; i >= 0; i--) {
+ spin_lock(&root->heat_range_map[i].lock);
+ n_list = seq_list_start(
+ &root->heat_range_map[i].node_list, *pos);
+ if (n_list) {
+ comm_item = container_of(n_list,
+ struct hot_comm_item, n_list);
+ hr = container_of(comm_item,
+ struct hot_range_item, hot_range);
+ kref_get(&hr->hot_range.refs);
+ spin_unlock(&root->heat_range_map[i].lock);
+ return hr;
+ }
+ spin_unlock(&root->heat_range_map[i].lock);
+ }
+
+ return NULL;
+}
+
+static void *hot_spot_range_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct hot_info *root = seq->private;
+ struct hot_range_item *hr_next, *hr = v;
+ struct hot_comm_item *comm_item;
+ struct list_head *n_list;
+ int i, j;
+ spin_lock(&hr->hot_range.lock);
+ i = (int)hot_raw_shift(hr->hot_range.hot_freq_data.last_temp,
+ (32 - HEAT_MAP_BITS), false);
+ spin_unlock(&hr->hot_range.lock);
+
+ spin_lock(&root->heat_range_map[i].lock);
+ n_list = seq_list_next(&hr->hot_range.n_list,
+ &root->heat_range_map[i].node_list, pos);
+ hot_range_item_put(hr);
+next:
+ j = i;
+ if (n_list) {
+ comm_item = container_of(n_list,
+ struct hot_comm_item, n_list);
+ hr_next = container_of(comm_item,
+ struct hot_range_item, hot_range);
+ kref_get(&hr_next->hot_range.refs);
+ spin_unlock(&root->heat_range_map[i].lock);
+ return hr_next;
+ } else if (--i >= 0) {
+ spin_unlock(&root->heat_range_map[j].lock);
+ spin_lock(&root->heat_range_map[i].lock);
+ n_list = seq_list_next(&root->heat_range_map[i].node_list,
+ &root->heat_range_map[i].node_list, pos);
+ goto next;
+ }
+
+ spin_unlock(&root->heat_range_map[j].lock);
+ return NULL;
+}
+
+static void *hot_spot_inode_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct hot_info *root = seq->private;
+ struct hot_inode_item *he;
+ struct hot_comm_item *comm_item;
+ struct list_head *n_list;
+ int i;
+
+ for (i = HEAT_MAP_SIZE - 1; i >= 0; i--) {
+ spin_lock(&root->heat_inode_map[i].lock);
+ n_list = seq_list_start(
+ &root->heat_inode_map[i].node_list, *pos);
+ if (n_list) {
+ comm_item = container_of(n_list,
+ struct hot_comm_item, n_list);
+ he = container_of(comm_item,
+ struct hot_inode_item, hot_inode);
+ kref_get(&he->hot_inode.refs);
+ spin_unlock(&root->heat_inode_map[i].lock);
+ return he;
+ }
+ spin_unlock(&root->heat_inode_map[i].lock);
+ }
+
+ return NULL;
+}
+
+static void *hot_spot_inode_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct hot_info *root = seq->private;
+ struct hot_inode_item *he_next, *he = v;
+ struct hot_comm_item *comm_item;
+ struct list_head *n_list;
+ int i, j;
+ spin_lock(&he->hot_inode.lock);
+ i = (int)hot_raw_shift(he->hot_inode.hot_freq_data.last_temp,
+ (32 - HEAT_MAP_BITS), false);
+ spin_unlock(&he->hot_inode.lock);
+
+ spin_lock(&root->heat_inode_map[i].lock);
+ n_list = seq_list_next(&he->hot_inode.n_list,
+ &root->heat_inode_map[i].node_list, pos);
+ hot_inode_item_put(he);
+next:
+ j = i;
+ if (n_list) {
+ comm_item = container_of(n_list,
+ struct hot_comm_item, n_list);
+ he_next = container_of(comm_item,
+ struct hot_inode_item, hot_inode);
+ kref_get(&he_next->hot_inode.refs);
+ spin_unlock(&root->heat_inode_map[i].lock);
+ return he_next;
+ } else if (--i >= 0) {
+ spin_unlock(&root->heat_inode_map[j].lock);
+ spin_lock(&root->heat_inode_map[i].lock);
+ n_list = seq_list_next(&root->heat_inode_map[i].node_list,
+ &root->heat_inode_map[i].node_list, pos);
+ goto next;
+ }
+
+ spin_unlock(&root->heat_inode_map[j].lock);
+ return NULL;
+}
+
+static const struct seq_operations hot_range_seq_ops = {
+ .start = hot_range_seq_start,
+ .next = hot_range_seq_next,
+ .stop = hot_range_seq_stop,
+ .show = hot_range_seq_show
+};
+
+static const struct seq_operations hot_inode_seq_ops = {
+ .start = hot_inode_seq_start,
+ .next = hot_inode_seq_next,
+ .stop = hot_inode_seq_stop,
+ .show = hot_inode_seq_show
+};
+
+static const struct seq_operations hot_spot_range_seq_ops = {
+ .start = hot_spot_range_seq_start,
+ .next = hot_spot_range_seq_next,
+ .stop = hot_range_seq_stop,
+ .show = hot_range_seq_show
+};
+
+static const struct seq_operations hot_spot_inode_seq_ops = {
+ .start = hot_spot_inode_seq_start,
+ .next = hot_spot_inode_seq_next,
+ .stop = hot_inode_seq_stop,
+ .show = hot_inode_seq_show
+};
+
+static int hot_range_seq_open(struct inode *inode, struct file *file)
+{
+ int ret = seq_open_private(file, &hot_range_seq_ops, 0);
+ if (ret == 0) {
+ struct seq_file *seq = file->private_data;
+ seq->private = inode->i_private;
+ }
+ return ret;
+}
+
+static int hot_inode_seq_open(struct inode *inode, struct file *file)
+{
+ int ret = seq_open_private(file, &hot_inode_seq_ops, 0);
+ if (ret == 0) {
+ struct seq_file *seq = file->private_data;
+ seq->private = inode->i_private;
+ }
+ return ret;
+}
+
+static int hot_spot_range_seq_open(struct inode *inode, struct file *file)
+{
+ int ret = seq_open_private(file, &hot_spot_range_seq_ops, 0);
+ if (ret == 0) {
+ struct seq_file *seq = file->private_data;
+ seq->private = inode->i_private;
+ }
+ return ret;
+}
+
+static int hot_spot_inode_seq_open(struct inode *inode, struct file *file)
+{
+ int ret = seq_open_private(file, &hot_spot_inode_seq_ops, 0);
+ if (ret == 0) {
+ struct seq_file *seq = file->private_data;
+ seq->private = inode->i_private;
+ }
+ return ret;
+}
+
+/* fops to override for printing range data */
+static const struct file_operations hot_debugfs_range_fops = {
+ .open = hot_range_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+/* fops to override for printing inode data */
+static const struct file_operations hot_debugfs_inode_fops = {
+ .open = hot_inode_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+/* fops to override for printing temperature data */
+static const struct file_operations hot_debugfs_spot_range_fops = {
+ .open = hot_spot_range_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static const struct file_operations hot_debugfs_spot_inode_fops = {
+ .open = hot_spot_inode_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static const struct hot_debugfs hot_debugfs[] = {
+ {
+ .name = "rt_stats_range",
+ .fops = &hot_debugfs_range_fops,
+ },
+ {
+ .name = "rt_stats_inode",
+ .fops = &hot_debugfs_inode_fops,
+ },
+ {
+ .name = "hot_spots_range",
+ .fops = &hot_debugfs_spot_range_fops,
+ },
+ {
+ .name = "hot_spots_inode",
+ .fops = &hot_debugfs_spot_inode_fops,
+ },
+};
+
+/* initialize debugfs */
+static int hot_debugfs_init(struct super_block *sb)
+{
+ static const char hot_name[] = "hot_track";
+ struct dentry *dentry;
+ int i, ret = 0;
+
+ /* Determine if hot debufs root has existed */
+ if (!hot_debugfs_root) {
+ hot_debugfs_root = debugfs_create_dir(hot_name, NULL);
+ if (IS_ERR(hot_debugfs_root)) {
+ ret = PTR_ERR(hot_debugfs_root);
+ return ret;
+ }
+ }
+
+ if (!S_ISDIR(hot_debugfs_root->d_inode->i_mode))
+ return -ENOTDIR;
+
+ /* create debugfs folder for this volume by mounted dev name */
+ sb->s_hot_root->vol_dentry =
+ debugfs_create_dir(sb->s_id, hot_debugfs_root);
+ if (IS_ERR(sb->s_hot_root->vol_dentry)) {
+ ret = PTR_ERR(sb->s_hot_root->vol_dentry);
+ goto err;
+ }
+
+ /* create debugfs hot data files */
+ for (i = 0; i < ARRAY_SIZE(hot_debugfs); i++) {
+ dentry = debugfs_create_file(hot_debugfs[i].name,
+ S_IFREG | S_IRUSR | S_IWUSR,
+ sb->s_hot_root->vol_dentry,
+ sb->s_hot_root,
+ hot_debugfs[i].fops);
+ if (IS_ERR(dentry)) {
+ ret = PTR_ERR(dentry);
+ goto err;
+ }
+ }
+
+ return 0;
+
+err:
+ debugfs_remove_recursive(sb->s_hot_root->vol_dentry);
+
+ if (list_empty(&hot_debugfs_root->d_subdirs)) {
+ debugfs_remove(hot_debugfs_root);
+ hot_debugfs_root = NULL;
+ }
+
+ return ret;
+}
+
+/* remove dentries for debugsfs */
+static void hot_debugfs_exit(struct super_block *sb)
+{
+ /* remove all debugfs entries recursively from the volume root */
+ if (sb->s_hot_root->vol_dentry)
+ debugfs_remove_recursive(sb->s_hot_root->vol_dentry);
+ else
+ BUG();
+
+ if (list_empty(&hot_debugfs_root->d_subdirs)) {
+ debugfs_remove(hot_debugfs_root);
+ hot_debugfs_root = NULL;
+ }
+}
+
/*
* Initialize kmem cache for hot_inode_item and hot_range_item.
*/
@@ -803,10 +1299,22 @@ int hot_track_init(struct super_block *sb)
sb->s_hot_root = root;
+ ret = hot_debugfs_init(sb);
+ if (ret) {
+ printk(KERN_ERR "%s: hot_debugfs_init error: %d\n",
+ __func__, ret);
+ goto failed_debugfs;
+ }
+
printk(KERN_INFO "VFS: Turning on hot data tracking\n");
return 0;
+failed_debugfs:
+ unregister_shrinker(&root->hot_shrink);
+ cancel_delayed_work_sync(&root->update_work);
+ destroy_workqueue(root->update_wq);
+ sb->s_hot_root = NULL;
failed_wq:
hot_map_exit(root);
hot_inode_tree_exit(root);
@@ -819,6 +1327,7 @@ void hot_track_exit(struct super_block *sb)
{
struct hot_info *root = sb->s_hot_root;
+ hot_debugfs_exit(sb);
unregister_shrinker(&root->hot_shrink);
cancel_delayed_work_sync(&root->update_work);
destroy_workqueue(root->update_wq);
diff --git a/fs/hot_tracking.h b/fs/hot_tracking.h
index 73d2a3e..a969940 100644
--- a/fs/hot_tracking.h
+++ b/fs/hot_tracking.h
@@ -53,4 +53,9 @@
#define AVW_DIVIDER_POWER 40 /* AVW - average delta between recent writes(ns) */
#define AVW_COEFF_POWER 0
+struct hot_debugfs {
+ const char *name;
+ const struct file_operations *fops;
+};
+
#endif /* __HOT_TRACKING__ */
diff --git a/include/linux/hot_tracking.h b/include/linux/hot_tracking.h
index bd55a34..a735f58 100644
--- a/include/linux/hot_tracking.h
+++ b/include/linux/hot_tracking.h
@@ -122,6 +122,7 @@ struct hot_info {
struct delayed_work update_work;
struct hot_type *hot_type;
struct shrinker hot_shrink;
+ struct dentry *vol_dentry;
};
/*
--
1.7.6.5
--
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