f2fs: detect idle time depending on user behavior

This patch adds last time that user requested filesystem operations.
This information is used to detect whether system is idle or not later.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

 Conflicts:
	Documentation/ABI/testing/sysfs-fs-f2fs

1 files changed, 100 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
new file mode 100644
index 000000000..e5200f354
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -0,0 +1,100 @@
+What:		/sys/fs/f2fs/<disk>/gc_max_sleep_time
+Date:		July 2013
+Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>
+Description:
+		 Controls the maximun sleep time for gc_thread. Time
+		 is in milliseconds.
+
+What:		/sys/fs/f2fs/<disk>/gc_min_sleep_time
+Date:		July 2013
+Contact:	"Namjae Jeon" <namjae.jeon@samsung.com>
+Description:
+		 Controls the minimum sleep time for gc_thread. Time
+		 is in milliseconds.
+
+What:		/sys/fs/f2fs/<disk>/gc_no_gc_sleep_time
+Date:		July 2013
+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.
+
+What:		/sys/fs/f2fs/<disk>/reclaim_segments
+Date:		October 2013
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the issue rate of segment discard commands.
+
+What:		/sys/fs/f2fs/<disk>/ipu_policy
+Date:		November 2013
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the in-place-update policy.
+
+What:		/sys/fs/f2fs/<disk>/min_ipu_util
+Date:		November 2013
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the FS utilization condition for the in-place-update
+		 policies.
+
+What:		/sys/fs/f2fs/<disk>/min_fsync_blocks
+Date:		September 2014
+Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
+Description:
+		 Controls the dirty page count condition for the in-place-update
+		 policies.
+
+What:		/sys/fs/f2fs/<disk>/max_small_discards
+Date:		November 2013
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the issue rate of small discard commands.
+
+What:		/sys/fs/f2fs/<disk>/max_victim_search
+Date:		January 2014
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the number of trials to find a victim segment.
+
+What:		/sys/fs/f2fs/<disk>/dir_level
+Date:		March 2014
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the directory level for large directory.
+
+What:		/sys/fs/f2fs/<disk>/ram_thresh
+Date:		March 2014
+Contact:	"Jaegeuk Kim" <jaegeuk.kim@samsung.com>
+Description:
+		 Controls the memory footprint used by f2fs.
+
+What:		/sys/fs/f2fs/<disk>/trim_sections
+Date:		February 2015
+Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
+Description:
+		 Controls the trimming rate in batch mode.
+
+What:		/sys/fs/f2fs/<disk>/cp_interval
+Date:		October 2015
+Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
+Description:
+		 Controls the checkpoint timing.
+
+What:		/sys/fs/f2fs/<disk>/idle_interval
+Date:		January 2016
+Contact:	"Jaegeuk Kim" <jaegeuk@kernel.org>
+Description:
+		 Controls the idle timing.
+
+What:		/sys/fs/f2fs/<disk>/ra_nid_pages
+Date:		October 2015
+Contact:	"Chao Yu" <chao2.yu@samsung.com>
+Description:
+		 Controls the count of nid pages to be readaheaded.