From: Zhi Yong Wu <wu...@linux.vnet.ibm.com>
Add three proc interfaces hot-reloc-interval, hot-reloc-threshold,
and hot-reloc-max-items under the dir /proc/sys/fs/ in order to
turn HOT_RELOC_INTERVAL, HOT_RELOC_THRESHOLD, and HOT_RELOC_MAX_ITEMS
into be tunable.
Signed-off-by: Zhi Yong Wu <wu...@linux.vnet.ibm.com>
---
fs/btrfs/hot_relocate.c | 26 +++++++++++++++++---------
fs/btrfs/hot_relocate.h | 4 ----
include/linux/btrfs.h | 4 ++++
kernel/sysctl.c | 22 ++++++++++++++++++++++
4 files changed, 43 insertions(+), 13 deletions(-)
diff --git a/fs/btrfs/hot_relocate.c b/fs/btrfs/hot_relocate.c
index 683e154..aa8c9f0 100644
--- a/fs/btrfs/hot_relocate.c
+++ b/fs/btrfs/hot_relocate.c
@@ -25,7 +25,7 @@
* The relocation code below operates on the heat map lists to identify
* hot or cold data logical file ranges that are candidates for relocation.
* The triggering mechanism for relocation is controlled by a global heat
- * threshold integer value (HOT_RELOC_THRESHOLD). Ranges are
+ * threshold integer value (sysctl_hot_reloc_threshold). Ranges are
* queued for relocation by the periodically executing relocate kthread,
* which updates the global heat threshold and responds to space pressure
* on the SSDs.
@@ -52,6 +52,15 @@
* (assuming, critically, the HOT_MOVE option is set at mount time).
*/
+int sysctl_hot_reloc_threshold = 150;
+EXPORT_SYMBOL_GPL(sysctl_hot_reloc_threshold);
+
+int sysctl_hot_reloc_interval __read_mostly = 120;
+EXPORT_SYMBOL_GPL(sysctl_hot_reloc_interval);
+
+int sysctl_hot_reloc_max_items __read_mostly = 250;
+EXPORT_SYMBOL_GPL(sysctl_hot_reloc_max_items);
+
static void hot_set_extent_bits(struct extent_io_tree *tree, u64 start,
u64 end, struct extent_state **cached_state,
gfp_t mask, int storage_type, int flag)
@@ -165,7 +174,7 @@ static int hot_calc_ssd_ratio(struct hot_reloc *hot_reloc)
static int hot_update_threshold(struct hot_reloc *hot_reloc,
int update)
{
- int thresh = hot_reloc->thresh;
+ int thresh = sysctl_hot_reloc_threshold;
int ratio = hot_calc_ssd_ratio(hot_reloc);
/* Sometimes update global threshold, others not */
@@ -189,7 +198,7 @@ static int hot_update_threshold(struct hot_reloc *hot_reloc,
thresh = 0;
}
- hot_reloc->thresh = thresh;
+ sysctl_hot_reloc_threshold = thresh;
return ratio;
}
@@ -280,7 +289,7 @@ static int hot_queue_extent(struct hot_reloc *hot_reloc,
hot_comm_item_put(ci);
spin_unlock(&he->i_lock);
- if (*counter >= HOT_RELOC_MAX_ITEMS)
+ if (*counter >= sysctl_hot_reloc_max_items)
break;
if (kthread_should_stop()) {
@@ -361,7 +370,7 @@ again:
while (1) {
lock_extent(tree, page_start, page_end);
ordered = btrfs_lookup_ordered_extent(inode,
- page_start);
+ page_start);
unlock_extent(tree, page_start, page_end);
if (!ordered)
break;
@@ -642,7 +651,7 @@ void hot_do_relocate(struct hot_reloc *hot_reloc)
run++;
ratio = hot_update_threshold(hot_reloc, !(run % 15));
- thresh = hot_reloc->thresh;
+ thresh = sysctl_hot_reloc_threshold;
INIT_LIST_HEAD(&hot_reloc->hot_relocq[TYPE_NONROT]);
@@ -652,7 +661,7 @@ void hot_do_relocate(struct hot_reloc *hot_reloc)
if (count_to_hot == 0)
return;
- count_to_cold = HOT_RELOC_MAX_ITEMS;
+ count_to_cold = sysctl_hot_reloc_max_items;
/* Don't move cold data to HDD unless there's space pressure */
if (ratio < HIGH_WATER_LEVEL)
@@ -734,7 +743,7 @@ static int hot_relocate_kthread(void *arg)
unsigned long delay;
do {
- delay = HZ * HOT_RELOC_INTERVAL;
+ delay = HZ * sysctl_hot_reloc_interval;
if (mutex_trylock(&hot_reloc->hot_reloc_mutex)) {
hot_do_relocate(hot_reloc);
mutex_unlock(&hot_reloc->hot_reloc_mutex);
@@ -766,7 +775,6 @@ int hot_relocate_init(struct btrfs_fs_info *fs_info)
fs_info->hot_reloc = hot_reloc;
hot_reloc->fs_info = fs_info;
- hot_reloc->thresh = HOT_RELOC_THRESHOLD;
for (i = 0; i < MAX_RELOC_TYPES; i++)
INIT_LIST_HEAD(&hot_reloc->hot_relocq[i]);
mutex_init(&hot_reloc->hot_reloc_mutex);
diff --git a/fs/btrfs/hot_relocate.h b/fs/btrfs/hot_relocate.h
index 077d9b3..ca30944 100644
--- a/fs/btrfs/hot_relocate.h
+++ b/fs/btrfs/hot_relocate.h
@@ -24,9 +24,6 @@ enum {
MAX_RELOC_TYPES
};
-#define HOT_RELOC_INTERVAL 120
-#define HOT_RELOC_THRESHOLD 150
-#define HOT_RELOC_MAX_ITEMS 250
#define HEAT_MAX_VALUE (MAP_SIZE - 1)
#define HIGH_WATER_LEVEL 75 /* when to raise the threshold */
@@ -38,7 +35,6 @@ enum {
struct hot_reloc {
struct btrfs_fs_info *fs_info;
struct list_head hot_relocq[MAX_RELOC_TYPES];
- int thresh;
struct task_struct *hot_reloc_kthread;
struct mutex hot_reloc_mutex;
};
diff --git a/include/linux/btrfs.h b/include/linux/btrfs.h
index 22d7991..7179819 100644
--- a/include/linux/btrfs.h
+++ b/include/linux/btrfs.h
@@ -3,4 +3,8 @@
#include <uapi/linux/btrfs.h>
+extern int sysctl_hot_reloc_threshold;
+extern int sysctl_hot_reloc_interval;
+extern int sysctl_hot_reloc_max_items;
+
#endif /* _LINUX_BTRFS_H */
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 11e4a3d..c1db57e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -62,6 +62,7 @@
#include <linux/capability.h>
#include <linux/binfmts.h>
#include <linux/sched/sysctl.h>
+#include <linux/btrfs.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
@@ -1617,6 +1618,27 @@ static struct ctl_table fs_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec,
},
+ {
+ .procname = "hot-reloc-threshold",
+ .data = &sysctl_hot_reloc_threshold,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "hot-reloc-interval",
+ .data = &sysctl_hot_reloc_interval,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {
+ .procname = "hot-reloc-max-items",
+ .data = &sysctl_hot_reloc_max_items,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
{ }
};
--
1.7.11.7
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