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 | 5 -----
include/linux/btrfs.h | 4 ++++
kernel/sysctl.c | 22 ++++++++++++++++++++++
4 files changed, 43 insertions(+), 14 deletions(-)
diff --git a/fs/btrfs/hot_relocate.c b/fs/btrfs/hot_relocate.c
index ae28b86..3a18555 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 nonrotating disks.
@@ -53,6 +53,15 @@
* (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);
+
/*
* Returns the ratio of nonrotating disks that are full.
* If no nonrotating disk is found, returns THRESH_MAX_VALUE + 1.
@@ -103,7 +112,7 @@ static int hot_calc_nonrot_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_nonrot_ratio(hot_reloc);
/* Sometimes update global threshold, others not */
@@ -127,7 +136,7 @@ static int hot_update_threshold(struct hot_reloc *hot_reloc,
thresh = 0;
}
- hot_reloc->thresh = thresh;
+ sysctl_hot_reloc_threshold = thresh;
return ratio;
}
@@ -215,7 +224,7 @@ static int hot_queue_extent(struct hot_reloc *hot_reloc,
*counter = *counter + 1;
}
- if (*counter >= HOT_RELOC_MAX_ITEMS)
+ if (*counter >= sysctl_hot_reloc_max_items)
break;
if (kthread_should_stop()) {
@@ -293,7 +302,7 @@ 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;
@@ -559,7 +568,7 @@ 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]);
@@ -569,7 +578,7 @@ 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)
@@ -653,7 +662,7 @@ 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);
@@ -685,7 +694,6 @@ 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 1b1cfb5..94defe6 100644
--- a/fs/btrfs/hot_relocate.h
+++ b/fs/btrfs/hot_relocate.h
@@ -18,10 +18,6 @@
#include "btrfs_inode.h"
#include "volumes.h"
-#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 */
#define LOW_WATER_LEVEL 50 /* when to lower the threshold */
@@ -32,7 +28,6 @@
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 6ee4338..3ab1a68 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>
@@ -1630,6 +1631,27 @@ 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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