1 files changed, 27 insertions, 5 deletions

diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram
index 70ec992514d0..a6148eaf91e5 100644
--- a/Documentation/ABI/testing/sysfs-block-zram
+++ b/Documentation/ABI/testing/sysfs-block-zram
@@ -77,11 +77,14 @@ What:		/sys/block/zram<id>/notify_free
 Date:           August 2010
 Contact:        Nitin Gupta <ngupta@vflare.org>
 Description:
-                The notify_free file is read-only and specifies the number of
-                swap slot free notifications received by this device. These
-                notifications are sent to a swap block device when a swap slot
-                is freed. This statistic is applicable only when this disk is
-                being used as a swap disk.
+                The notify_free file is read-only. Depending on device usage
+                scenario it may account a) the number of pages freed because
+                of swap slot free notifications or b) the number of pages freed
+                because of REQ_DISCARD requests sent by bio. The former ones
+                are sent to a swap block device when a swap slot is freed, which
+                implies that this disk is being used as a swap disk. The latter
+                ones are sent by filesystem mounted with discard option,
+                whenever some data blocks are getting discarded.
 
 What:           /sys/block/zram<id>/zero_pages
 Date:           August 2010
@@ -119,3 +122,22 @@ Description:
                 efficiency can be calculated using compr_data_size and this
                 statistic.
                 Unit: bytes
+
+What:           /sys/block/zram<id>/mem_used_max
+Date:           August 2014
+Contact:        Minchan Kim <minchan@kernel.org>
+Description:
+                The mem_used_max file is read/write and specifies the amount
+                of maximum memory zram have consumed to store compressed data.
+                For resetting the value, you should write "0". Otherwise,
+                you could see -EINVAL.
+                Unit: bytes
+
+What:           /sys/block/zram<id>/mem_limit
+Date:           August 2014
+Contact:        Minchan Kim <minchan@kernel.org>
+Description:
+                The mem_limit file is read/write and specifies the maximum
+                amount of memory ZRAM can use to store the compressed data.  The
+                limit could be changed in run time and "0" means disable the
+                limit.  No limit is the initial state.  Unit: bytes