From: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
Introduce two proc interfaces hot-mem-high-thresh and
hot-mem-low-thresh to cap the memory which is consumed by
hot_inode_item and hot_range_item, and they will be in
the unit of 1M bytes.
Signed-off-by: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
---
fs/hot_tracking.c | 40 ++++++++++++++++++++++++++++++++++++++--
fs/hot_tracking.h | 26 ++++++++++++++++++++++++++
include/linux/hot_tracking.h | 6 ++++++
kernel/sysctl.c | 14 ++++++++++++++
4 files changed, 84 insertions(+), 2 deletions(-)
diff --git a/fs/hot_tracking.c b/fs/hot_tracking.c
index 0d265b9..915b48b 100644
--- a/fs/hot_tracking.c
+++ b/fs/hot_tracking.c
@@ -23,6 +23,12 @@
static struct dentry *hot_debugfs_root;
+int sysctl_hot_mem_high_thresh __read_mostly = 0;
+EXPORT_SYMBOL_GPL(sysctl_hot_mem_high_thresh);
+
+int sysctl_hot_mem_low_thresh __read_mostly = 0;
+EXPORT_SYMBOL_GPL(sysctl_hot_mem_low_thresh);
+
int sysctl_hot_update_interval __read_mostly = 300;
EXPORT_SYMBOL_GPL(sysctl_hot_update_interval);
@@ -122,10 +128,14 @@ static void hot_comm_item_unlink(struct hot_info *root,
spin_lock(&he->i_lock);
rb_erase(&ci->rb_node, &he->hot_range_tree);
spin_unlock(&he->i_lock);
+
+ hot_mem_limit_sub(root, sizeof(struct hot_range_item));
} else {
spin_lock(&root->t_lock);
rb_erase(&ci->rb_node, &root->hot_inode_tree);
spin_unlock(&root->t_lock);
+
+ hot_mem_limit_sub(root, sizeof(struct hot_inode_item));
}
hot_comm_item_put(ci);
@@ -199,13 +209,15 @@ redo:
else {
hot_comm_item_get(&he->hot_inode);
spin_unlock(&root->t_lock);
- if (he_new)
+ if (he_new) {
/*
* Lost the race. Somebody else inserted
* the item for the inode. Free the
* newly allocated item.
*/
kmem_cache_free(hot_inode_item_cachep, he_new);
+ hot_mem_limit_sub(root, sizeof(struct hot_inode_item));
+ }
if (test_bit(HOT_DELETING, &he->hot_inode.delete_flag))
return ERR_PTR(-ENOENT);
@@ -231,6 +243,7 @@ redo:
if (!he_new)
return ERR_PTR(-ENOMEM);
+ hot_mem_limit_add(root, sizeof(struct hot_inode_item));
hot_inode_item_init(he_new, root, ino);
goto redo;
@@ -280,13 +293,15 @@ redo:
else {
hot_comm_item_get(&hr->hot_range);
spin_unlock(&he->i_lock);
- if(hr_new)
+ if(hr_new) {
/*
* Lost the race. Somebody else inserted
* the item for the range. Free the
* newly allocated item.
*/
kmem_cache_free(hot_range_item_cachep, hr_new);
+ hot_mem_limit_sub(root, sizeof(struct hot_range_item));
+ }
if (test_bit(HOT_DELETING, &hr->hot_range.delete_flag))
return ERR_PTR(-ENOENT);
@@ -312,6 +327,7 @@ redo:
if (!hr_new)
return ERR_PTR(-ENOMEM);
+ hot_mem_limit_add(root, sizeof(struct hot_range_item));
hot_range_item_init(hr_new, he, start);
goto redo;
@@ -570,6 +586,22 @@ static void hot_item_evictor(struct hot_info *root, unsigned long work,
}
}
+static void hot_mem_evictor(struct hot_info *root)
+{
+ unsigned long work;
+
+ if (sysctl_hot_mem_high_thresh == 0)
+ return;
+
+ /* note: sysctl_** is in the unit of 1M bytes */
+ if (hot_mem_limit(root) <= sysctl_hot_mem_high_thresh * 1024 * 1024)
+ return;
+
+ work = hot_mem_limit(root) - sysctl_hot_mem_low_thresh * 1024 * 1024;
+
+ hot_item_evictor(root, work, hot_mem_limit);
+}
+
/*
* Every sync period we update temperatures for
* each hot inode item and hot range item for aging
@@ -584,6 +616,8 @@ static void hot_update_worker(struct work_struct *work)
struct hot_inode_item *he;
int i, j;
+ hot_mem_evictor(root);
+
rcu_read_lock();
node = rb_first(&root->hot_inode_tree);
while (node) {
@@ -1235,6 +1269,7 @@ int hot_track_init(struct super_block *sb)
if (IS_ERR(root))
return PTR_ERR(root);
+ hot_mem_limit_init(root);
sb->s_hot_root = root;
ret = hot_debugfs_init(sb);
@@ -1264,6 +1299,7 @@ void hot_track_exit(struct super_block *sb)
{
struct hot_info *root = sb->s_hot_root;
+ hot_mem_limit_exit(root);
hot_debugfs_exit(sb);
hot_tree_exit(root);
sb->s_hot_root = NULL;
diff --git a/fs/hot_tracking.h b/fs/hot_tracking.h
index d1ab48b..be9f5cd 100644
--- a/fs/hot_tracking.h
+++ b/fs/hot_tracking.h
@@ -45,4 +45,30 @@ struct hot_debugfs {
const struct file_operations *fops;
};
+/* Memory Tracking Functions. */
+static inline unsigned long hot_mem_limit(struct hot_info *root)
+{
+ return percpu_counter_read(&root->mem);
+}
+
+static inline void hot_mem_limit_sub(struct hot_info *root, int i)
+{
+ percpu_counter_add(&root->mem, -i);
+}
+
+static inline void hot_mem_limit_add(struct hot_info *root, int i)
+{
+ percpu_counter_add(&root->mem, i);
+}
+
+static inline void hot_mem_limit_init(struct hot_info *root)
+{
+ percpu_counter_init(&root->mem, 0);
+}
+
+static inline void hot_mem_limit_exit(struct hot_info *root)
+{
+ percpu_counter_destroy(&root->mem);
+}
+
#endif /* __HOT_TRACKING__ */
diff --git a/include/linux/hot_tracking.h b/include/linux/hot_tracking.h
index f5c5769..03e5026 100644
--- a/include/linux/hot_tracking.h
+++ b/include/linux/hot_tracking.h
@@ -16,6 +16,7 @@
#define _LINUX_HOTTRACK_H
#include <linux/types.h>
+#include <linux/percpu_counter.h>
struct hot_heat_info {
__u64 avg_delta_reads;
@@ -108,10 +109,15 @@ struct hot_info {
struct shrinker hot_shrink;
struct dentry *debugfs_dentry;
atomic_t run_debugfs;
+
+ struct percpu_counter mem ____cacheline_aligned_in_smp;
};
/* set how often to update temperatures (seconds) */
extern int sysctl_hot_update_interval;
+/* note: sysctl_** is in the unit of 1M bytes */
+extern int sysctl_hot_mem_high_thresh;
+extern int sysctl_hot_mem_low_thresh;
/*
* Hot data tracking ioctls:
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 1ba111d..753585d 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1617,6 +1617,20 @@ static struct ctl_table fs_table[] = {
.extra1 = &pipe_min_size,
},
{
+ .procname = "hot-mem-high-thresh",
+ .data = &sysctl_hot_mem_high_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "hot-mem-low-thresh",
+ .data = &sysctl_hot_mem_low_thresh,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
.procname = "hot-update-interval",
.data = &sysctl_hot_update_interval,
.maxlen = sizeof(int),
--
1.7.11.7
--
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