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authorNamjae Jeon <namjae.jeon@samsung.com>2013-08-04 23:10:15 +0900
committerJaegeuk Kim <jaegeuk.kim@samsung.com>2013-08-06 22:00:18 +0900
commitd2dc095f4280ad5fdea33769e8e119fd16648426 (patch)
treef97a7bd3a06822c463e678770fb63dab52d0bc94
parentb59d0bae6ca30c496f298881616258f9cde0d9c6 (diff)
downloadop-kernel-dev-d2dc095f4280ad5fdea33769e8e119fd16648426.zip
op-kernel-dev-d2dc095f4280ad5fdea33769e8e119fd16648426.tar.gz
f2fs: add sysfs entries to select the gc policy
Add sysfs entry gc_idle to control the gc policy. Where gc_idle = 1 corresponds to selecting a cost benefit approach, while gc_idle = 2 corresponds to selecting a greedy approach to garbage collection. The selection is mutually exclusive one approach will work at any point. If gc_idle = 0, then this option is disabled. Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com> Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com> [Jaegeuk Kim: change the select_gc_type() flow slightly] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
-rw-r--r--Documentation/ABI/testing/sysfs-fs-f2fs6
-rw-r--r--Documentation/filesystems/f2fs.txt6
-rw-r--r--fs/f2fs/gc.c16
-rw-r--r--fs/f2fs/gc.h3
-rw-r--r--fs/f2fs/super.c2
5 files changed, 30 insertions, 3 deletions
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 98e53a0..31942ef 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -18,3 +18,9 @@ Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
Description:
Controls the default sleep time for gc_thread. Time
is in milliseconds.
+
+What: /sys/fs/f2fs/<disk>/gc_idle
+Date: July 2013
+Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
+Description:
+ Controls the victim selection policy for garbage collection.
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 5daf3bb..3cd27be 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -158,6 +158,12 @@ Files in /sys/fs/f2fs/<devname>
time for the garbage collection thread. Time is
in milliseconds.
+ gc_idle This parameter controls the selection of victim
+ policy for garbage collection. Setting gc_idle = 0
+ (default) will disable this option. Setting
+ gc_idle = 1 will select the Cost Benefit approach
+ & setting gc_idle = 2 will select the greedy aproach.
+
================================================================================
USAGE
================================================================================
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 60d4f67..d286d8b 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -106,6 +106,8 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
+ gc_th->gc_idle = 0;
+
sbi->gc_thread = gc_th;
init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
@@ -130,9 +132,17 @@ void stop_gc_thread(struct f2fs_sb_info *sbi)
sbi->gc_thread = NULL;
}
-static int select_gc_type(int gc_type)
+static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
{
- return (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
+ int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
+
+ if (gc_th && gc_th->gc_idle) {
+ if (gc_th->gc_idle == 1)
+ gc_mode = GC_CB;
+ else if (gc_th->gc_idle == 2)
+ gc_mode = GC_GREEDY;
+ }
+ return gc_mode;
}
static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
@@ -145,7 +155,7 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
p->dirty_segmap = dirty_i->dirty_segmap[type];
p->ofs_unit = 1;
} else {
- p->gc_mode = select_gc_type(gc_type);
+ p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
p->ofs_unit = sbi->segs_per_sec;
}
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
index f4bf44c..c22dee9 100644
--- a/fs/f2fs/gc.h
+++ b/fs/f2fs/gc.h
@@ -30,6 +30,9 @@ struct f2fs_gc_kthread {
unsigned int min_sleep_time;
unsigned int max_sleep_time;
unsigned int no_gc_sleep_time;
+
+ /* for changing gc mode */
+ unsigned int gc_idle;
};
struct inode_entry {
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index e161a24..94c0e20 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -148,12 +148,14 @@ static struct f2fs_attr f2fs_attr_##_name = { \
F2FS_RW_ATTR(gc_min_sleep_time, min_sleep_time);
F2FS_RW_ATTR(gc_max_sleep_time, max_sleep_time);
F2FS_RW_ATTR(gc_no_gc_sleep_time, no_gc_sleep_time);
+F2FS_RW_ATTR(gc_idle, gc_idle);
#define ATTR_LIST(name) (&f2fs_attr_##name.attr)
static struct attribute *f2fs_attrs[] = {
ATTR_LIST(gc_min_sleep_time),
ATTR_LIST(gc_max_sleep_time),
ATTR_LIST(gc_no_gc_sleep_time),
+ ATTR_LIST(gc_idle),
NULL,
};
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