f2fs: export migration_granularity sysfs entry
Add one sysfs entry to control migration granularity of GC in large
section f2fs, it can be tuned to mitigate heavy overhead of migrating
huge number of blocks in large section.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 6b5e31f..e09db01 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -92,6 +92,15 @@
Description:
Controls the number of trials to find a victim segment.
+What: /sys/fs/f2fs/<disk>/migration_granularity
+Date: October 2018
+Contact: "Chao Yu" <yuchao0@huawei.com>
+Description:
+ Controls migration granularity of garbage collection on large
+ section, it can let GC move partial segment{s} of one section
+ in one GC cycle, so that dispersing heavy overhead GC to
+ multiple lightweight one.
+
What: /sys/fs/f2fs/<disk>/dir_level
Date: March 2014
Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>