[PATCH 8/8] Document sysfs entries

Nitin Gupta
2010-07-16T12:38:22Z

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
---
Documentation/ABI/testing/sysfs-kernel-mm-zcache | 53 ++++++++++++++++++++++
1 files changed, 53 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-zcache

diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-zcache b/Documentation/ABI/testing/sysfs-kernel-mm-zcache
new file mode 100644
index 0000000..7ee3f31
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-zcache
@@ -0,0 +1,53 @@
+What: /sys/kernel/mm/zcache
+Date: July 2010
+Contact: Nitin Gupta <ngupta@vflare.org>
+Description:
+ /sys/kernel/mm/zcache directory contains compressed cache
+ statistics for each pool. A separate pool is created for
+ every mount instance of cleancache-aware filesystems.
+
+What: /sys/kernel/mm/zcache/pool<id>/zero_pages
+Date: July 2010
+Contact: Nitin Gupta <ngupta@vflare.org>
+Description:
+ The zero_pages file is read-only and specifies number of zero
+ filled pages found in this pool.
+
+What: /sys/kernel/mm/zcache/pool<id>/orig_data_size
+Date: July 2010
+Contact: Nitin Gupta <ngupta@vflare.org>
+Description:
+ The orig_data_size file is read-only and specifies uncompressed
+ size of data stored in this pool. This excludes zero-filled
+ pages (zero_pages) since no memory is allocated for them.
+ Unit: bytes
+
+What: /sys/kernel/mm/zcache/pool<id>/compr_data_size
+Date: July 2010
+Contact: Nitin Gupta <ngupta@vflare.org>
+Description:
+ The compr_data_size file is read-only and specifies compressed
+ size of data stored in this pool. So, compression ratio can be
+ calculated using orig_data_size and this statistic.
+ Unit: bytes
+
+What: /sys/kernel/mm/zcache/pool<id>/mem_used_total
+Date: July 2010
+Contact: Nitin Gupta <ngupta@vflare.org>
+Description:
+ The mem_used_total file is read-only and specifies the amount
+ of memory, including allocator fragmentation and metadata
+ overhead, allocated for this pool. So, allocator space
+ efficiency can be calculated using compr_data_size and this
+ statistic.
+ Unit: bytes
+
+What: /sys/kernel/mm/zcache/pool<id>/memlimit
+Date: July 2010
+Contact: Nitin Gupta <ngupta@vflare.org>
+Description:
+ The memlimit file is read-write and specifies upper bound on
+ the compressed data size (compr_data_dize) stored in this pool.
+ The value specified is rounded down to nearest multiple of
+ PAGE_SIZE.
+ Unit: bytes
\ No newline at end of file
--
1.7.1.1