selftests/zram: Adding zram tests

zram: Compressed RAM based block devices
----------------------------------------
The zram module creates RAM based block devices named /dev/zram<id>
(<id> = 0, 1, ...). Pages written to these disks are compressed and stored
in memory itself. These disks allow very fast I/O and compression provides
good amounts of memory savings. Some of the usecases include /tmp storage,
use as swap disks, various caches under /var and maybe many more :)

Statistics for individual zram devices are exported through sysfs nodes at
/sys/block/zram<id>/

This patch is to validate the zram functionality. Test interacts with block
device /dev/zram<id> and sysfs nodes /sys/block/zram<id>/

zram.sh: sanity check of CONFIG_ZRAM and to run zram01 and zram02 tests
zram01.sh: creates general purpose ram disks with different filesystems
zram02.sh: creates block device for swap
zram_lib.sh: create library with initialization/cleanup functions
README: ZRAM introduction and Kconfig required.
Makefile: To run zram tests

zram test output
-----------------
./zram.sh
--------------------
running zram tests
--------------------
/dev/zram0 device file found: OK
set max_comp_streams to zram device(s)
/sys/block/zram0/max_comp_streams = '2' (1/1)
zram max streams: OK
test that we can set compression algorithm
supported algs: [lzo] lz4
/sys/block/zram0/comp_algorithm = 'lzo' (1/1)
zram set compression algorithm: OK
set disk size to zram device(s)
/sys/block/zram0/disksize = '2097152' (1/1)
zram set disksizes: OK
set memory limit to zram device(s)
/sys/block/zram0/mem_limit = '2M' (1/1)
zram set memory limit: OK
make ext4 filesystem on /dev/zram0
zram mkfs.ext4: OK
mount /dev/zram0
zram mount of zram device(s): OK
fill zram0...
zram0 can be filled with '1932' KB
zram used 3M, zram disk sizes 2097152M
zram compression ratio: 699050.66:1: OK
zram cleanup
zram01 : [PASS]

/dev/zram0 device file found: OK
set max_comp_streams to zram device(s)
/sys/block/zram0/max_comp_streams = '2' (1/1)
zram max streams: OK
set disk size to zram device(s)
/sys/block/zram0/disksize = '1048576' (1/1)
zram set disksizes: OK
set memory limit to zram device(s)
/sys/block/zram0/mem_limit = '1M' (1/1)
zram set memory limit: OK
make swap with zram device(s)
done with /dev/zram0
zram making zram mkswap and swapon: OK
zram swapoff: OK
zram cleanup
zram02 : [PASS]

CC: Shuah Khan <shuahkh@osg.samsung.com>
CC: Tyler Baker <tyler.baker@linaro.org>
CC: Milosz Wasilewski <milosz.wasilewski@linaro.org>
CC: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-By: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/tools/testing/selftests/zram/README b/tools/testing/selftests/zram/README
new file mode 100644
index 000000000000..eb17917c8a3a
--- /dev/null
+++ b/tools/testing/selftests/zram/README
@@ -0,0 +1,40 @@
+zram: Compressed RAM based block devices
+----------------------------------------
+* Introduction
+
+The zram module creates RAM based block devices named /dev/zram<id>
+(<id> = 0, 1, ...). Pages written to these disks are compressed and stored
+in memory itself. These disks allow very fast I/O and compression provides
+good amounts of memory savings. Some of the usecases include /tmp storage,
+use as swap disks, various caches under /var and maybe many more :)
+
+Statistics for individual zram devices are exported through sysfs nodes at
+/sys/block/zram<id>/
+
+Kconfig required:
+CONFIG_ZRAM=y
+CONFIG_ZRAM_LZ4_COMPRESS=y
+CONFIG_ZPOOL=y
+CONFIG_ZSMALLOC=y
+
+ZRAM Testcases
+--------------
+zram_lib.sh: create library with initialization/cleanup functions
+zram.sh: For sanity check of CONFIG_ZRAM and to run zram01 and zram02
+
+Two functional tests: zram01 and zram02:
+zram01.sh: creates general purpose ram disks with ext4 filesystems
+zram02.sh: creates block device for swap
+
+Commands required for testing:
+ - bc
+ - dd
+ - free
+ - awk
+ - mkswap
+ - swapon
+ - swapoff
+ - mkfs/ mkfs.ext4
+
+For more information please refer:
+kernel-source-tree/Documentation/blockdev/zram.txt