3.2.3. LTP-DDT Validation¶
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LTP-DDT is a test application used by Texas Instruments to validate Linux releases.
LTP-DDT uses LTP’s test infrastructure, such as:
Test execution drivers (PAN)
Top-level test scripts (i.e. runltp)
Same Folder Hierarchy and test case definition format
LTP-DDT test cases are LTP test cases and vice-versa.
The main additions or ‘enhacements’ of LTP-DDT compared to LTP are:
PLATFORM files. LTP-DDT uses PLATFORM files to identify platform hardware and software features.
OVERRIDE mechanism. Default test case parameters are automatically overridden based on PLATFORM features.
ATOMIC scripts. Code reuse is foster by writing scripts that implement small well-defined actions. Test scripts rely on these atomic scripts to execute their actions.
AUTOMATIC FILTERING. Test cases are filtered based on the test requirements and the PLATFORM features.
TESTCASE ANNOTATIONS. Test scenario files are annotated with following annotations @name, @desc, @requires and @setup_requires. The @requires and @setup_requires are used to select test cases at run time based on the PLATFORM features.
All LTP-DDT test cases and test code reside in <testcases-root>/ddt/ and <testcode-root>/ddt/ folders respectively.
Easy to use (automatically filter test cases not applicable for platform)
Easy to support new platforms (just define the platform file)
Test cases can be easily wrap or imported to Test Management Systems (Use of testcase annotations facilitates this)
High Code Reuse (atomic scripts and test scripts are reused and parameters are adjusted on the fly)
latency under different use cases (important for RT kernel)
mm (ltp’s memory management)
programmable real-time unit (PRU)
system (use-cases, e.g. multiple tests running in parallel)
usb host (multiple tests with different classes)
Device Under Tests Supported
Supported platforms with LTP-DDT - can be found here
Host Platform Requirements
Linux host is required :
for compiling LTP-DDT.
to host the NFS server to boot the EVM with NFS as root filesystem
to run host utilities - e.g.iperf
Host Software Requirements
GCC Tool chain for ARM
Serial console terminal application
TFTP and NFS servers. NFS server is required only in case of NFS boot.
iperf utility on the host.
LTP-DDT relies on other open source test tools. The following test tools must be available in the target filesystem to run ltp-ddt:
There is an Arago/OE recipe here that builds a filesystem image w/ the above tools plus:
Clone the project
git clone https://git.ti.com/git/test-automation/ltp-ddt.git
Run DDT tests the same way you run LTP tests. Use ltprun program and pass to
it the test scenario file in the runtest directory (option -f) to run and the platform (option -P) to use. For example:
./runltp -P am180x-evm -f ddt/lmbench
In addition to selecting test scenarios using -f option, users can also
The runltp script have lot of options. Some useful ones for stress tests are:
-t DURATION: Define duration of the test in s,m,h,d. -x INSTANCES: Run multiple test instances in parallel. -c <options>: Run test under additional background CPU load -D <options>: Run test under additional background load on Secondary storage -m <options>: Run test under additional background load on Main memory -i <options>: Run test under additional background load on IO Bus -n : Run test with network traffic in background.
Please refer to README-DDT file section 8) for more details.
Running NAND Sanity Tests
– Run all NAND sanity tests
Using below command to run NAND sanity tests.
./runltp -P <platform> -s "NAND_S_" -S skiplist
If there are more than one flash filesystem supported, say, jffs2 and ubifs and you don’t run jffs2 test cases. You need create a file called ‘skiplist’ (this filename could be anything) and put to-be-skipped test case tag in this file. Here is the content of skiplist to skip jffs2 test cases.
@ cat skiplist _JFFS2
– Run NAND performance test
./runltp -P <platform> -s "NAND_L_PERF" -S skiplist