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: Chandra Seetharaman <sekharan@xxxxxxxxxx>
Signed-off-by: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
---
fs/hot_tracking.c | 32 ++++++++++++++++++++++++++++++++
fs/hot_tracking.h | 23 +++++++++++++++++++++++
include/linux/hot_tracking.h | 4 ++++
kernel/sysctl.c | 14 ++++++++++++++
4 files changed, 73 insertions(+)
diff --git a/fs/hot_tracking.c b/fs/hot_tracking.c
index a3742b7..3a08b66 100644
--- a/fs/hot_tracking.c
+++ b/fs/hot_tracking.c
@@ -15,6 +15,12 @@
#include <linux/list_sort.h>
#include "hot_tracking.h"
+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 = 150;
EXPORT_SYMBOL_GPL(sysctl_hot_update_interval);
@@ -44,6 +50,7 @@ static void hot_range_item_init(struct hot_range_item *hr,
hr->len = hot_bit_shift(1, RANGE_BITS, true);
hr->hot_inode = he;
atomic_long_inc(&he->hot_root->hot_cnt);
+ hot_mem_limit_add(he->hot_root, sizeof(struct hot_range_item));
}
static void hot_range_item_free_cb(struct rcu_head *head)
@@ -53,6 +60,7 @@ static void hot_range_item_free_cb(struct rcu_head *head)
struct hot_info *root = hr->hot_inode->hot_root;
atomic_long_dec(&root->hot_cnt);
+ hot_mem_limit_sub(root, sizeof(struct hot_range_item));
kmem_cache_free(hot_range_item_cachep, hr);
}
@@ -238,6 +246,7 @@ static void hot_inode_item_init(struct hot_inode_item *he,
he->hot_root = root;
spin_lock_init(&he->i_lock);
atomic_long_inc(&root->hot_cnt);
+ hot_mem_limit_add(root, sizeof(struct hot_inode_item));
}
static void hot_inode_item_free_cb(struct rcu_head *head)
@@ -247,6 +256,7 @@ static void hot_inode_item_free_cb(struct rcu_head *head)
struct hot_info *root = he->hot_root;
atomic_long_dec(&root->hot_cnt);
+ hot_mem_limit_sub(root, sizeof(struct hot_inode_item));
kmem_cache_free(hot_inode_item_cachep, he);
}
@@ -559,6 +569,25 @@ static void hot_item_evict(struct hot_info *root, unsigned long work,
}
}
+static void hot_mem_evict(struct hot_info *root)
+{
+ unsigned long sum, thresh;
+
+ if (sysctl_hot_mem_low_thresh == 0 ||
+ sysctl_hot_mem_high_thresh == 0 ||
+ (sysctl_hot_mem_high_thresh < sysctl_hot_mem_low_thresh))
+ return;
+
+ sum = hot_mem_limit_sum(root);
+ /* Note: sysctl_** is in the unit of 1M bytes */
+ thresh = sysctl_hot_mem_high_thresh;
+ thresh *= 1024 * 1024;
+ if (sum <= thresh)
+ return;
+
+ hot_item_evict(root, sum - thresh, hot_mem_limit_sum);
+}
+
/*
* Every sync period we update temperatures for
* each hot inode item and hot range item for aging
@@ -572,6 +601,8 @@ static void hot_update_worker(struct work_struct *work)
struct rb_node *node;
int i;
+ hot_mem_evict(root);
+
rcu_read_lock();
node = rb_first(&root->hot_inode_tree);
while (node) {
@@ -785,6 +816,7 @@ int hot_track_init(struct super_block *sb)
goto err;
}
+ hot_mem_limit_init(root);
sb->s_hot_root = root;
printk(KERN_INFO "VFS: Turning on hot tracking\n");
diff --git a/fs/hot_tracking.h b/fs/hot_tracking.h
index 23b1339..c9efa5b 100644
--- a/fs/hot_tracking.h
+++ b/fs/hot_tracking.h
@@ -40,4 +40,27 @@
#define AVW_DIVIDER_POWER 40 /* AVW - average delta between recent writes(ns) */
#define AVW_COEFF_POWER 0
+/* Memory Tracking Functions. */
+static inline unsigned long hot_mem_limit_sum(struct hot_info *root)
+{
+ return atomic_long_read(&root->mem);
+}
+
+static inline void hot_mem_limit_sub(struct hot_info *root,
+ unsigned long count)
+{
+ atomic_long_sub(count, &root->mem);
+}
+
+static inline void hot_mem_limit_add(struct hot_info *root,
+ unsigned long count)
+{
+ atomic_long_add(count, &root->mem);
+}
+
+static inline void hot_mem_limit_init(struct hot_info *root)
+{
+ atomic_long_set(&root->mem, 0);
+}
+
#endif /* __HOT_TRACKING__ */
diff --git a/include/linux/hot_tracking.h b/include/linux/hot_tracking.h
index 92e3547..64e1c8a 100644
--- a/include/linux/hot_tracking.h
+++ b/include/linux/hot_tracking.h
@@ -99,10 +99,14 @@ struct hot_info {
struct workqueue_struct *update_wq;
struct delayed_work update_work;
struct shrinker hot_shrink;
+ atomic_long_t mem;
};
/* 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 398cc05..c56aa34 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1632,6 +1632,20 @@ 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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