7. dpdk-test-bbdev Application

The dpdk-test-bbdev tool is a Data Plane Development Kit (DPDK) utility that allows measuring performance parameters of PMDs available in the bbdev framework. Tests available for execution are: latency, throughput, validation, bler and sanity tests. Execution of tests can be customized using various parameters passed to a python running script.

7.1. Running the Application

The tool application has a number of command line options:

test-bbdev.py [-h] [-p TESTAPP_PATH] [-e EAL_PARAMS] [-t TIMEOUT]
                   [-c TEST_CASE [TEST_CASE ...]]
                   [-v TEST_VECTOR [TEST_VECTOR...]] [-n NUM_OPS]
                   [-b BURST_SIZE [BURST_SIZE ...]] [-l NUM_LCORES]
                   [-t MAX_ITERS [MAX_ITERS ...]]
                   [-s SNR [SNR ...]]

7.1.1. command-line Options

The following are the command-line options:

-h, --help
Shows help message and exit.
-p TESTAPP_PATH, --testapp_path TESTAPP_PATH
Indicates the path to the bbdev test app. If not specified path is set based on “../..” concatenated with “/build/app/dpdk-test-bbdev”.
-e EAL_PARAMS, --eal_params EAL_PARAMS
Specifies EAL arguments which are passed to the test app. For more details, refer to DPDK documentation at EAL parameters.
-t TIMEOUT, --timeout TIMEOUT
Specifies timeout in seconds. If not specified timeout is set to 300 seconds.
-c TEST_CASE [TEST_CASE ...], --test_cases TEST_CASE [TEST_CASE ...]

Defines test cases to run. If not specified all available tests are run.

Example usage:

./test-bbdev.py -c validation
Runs validation test suite
./test-bbdev.py -c latency throughput
Runs latency and throughput test suites
-v TEST_VECTOR [TEST_VECTOR ...], --test_vector TEST_VECTOR [TEST_VECTOR ...]

Specifies paths to the test vector files. If not specified path is set based on “../..” concatenated with “/app/test-bbdev/test_vectors/bbdev_null.data” and indicates default data file.

Example usage:

./test-bbdev.py -v app/test-bbdev/test_vectors/turbo_dec_test1.data
Fills vector based on turbo_dec_test1.data file and runs all tests
./test-bbdev.py -v turbo_dec_test1.data turbo_enc_test2.data
The bbdev test app is executed twice. First time vector is filled based on turbo_dec_test1.data file and second time based on turb_enc_test2.data file. For both executions all tests are run.
-n NUM_OPS, --num_ops NUM_OPS
Specifies number of operations to process on device. If not specified num_ops is set to 32 operations.
-l NUM_LCORES, --num_lcores NUM_LCORES
Specifies number of lcores to run. If not specified num_lcores is set according to value from RTE configuration (EAL coremask)
-b BURST_SIZE [BURST_SIZE ...], --burst-size BURST_SIZE [BURST_SIZE ...]
Specifies operations enqueue/dequeue burst size. If not specified burst_size is set to 32. Maximum is 512.
-t MAX_ITERS [MAX_ITERS ...], --iter_max MAX_ITERS [MAX_ITERS ...]
Specifies LDPC decoder operations maximum number of iterations for throughput and bler tests. If not specified iter_max is set to 6.
-s SNR [SNR ...], --snr SNR [SNR ...]
Specifies for LDPC decoder operations the SNR in dB used when generating LLRs for bler tests. If not specified snr is set to 0 dB.

7.1.2. Test Cases

There are 7 main test cases that can be executed using testbbdev tool:

  • Sanity checks [-c unittest]
    • Performs sanity checks on BBDEV interface, validating basic functionality
  • Validation tests [-c validation]
    • Performs full operation of enqueue and dequeue
    • Compares the dequeued data buffer with a expected values in the test vector (TV) being used
    • Fails if any dequeued value does not match the data in the TV
  • Offload Cost measurement [-c offload]
    • Measures the CPU cycles consumed from the receipt of a user enqueue until it is put on the device queue
    • The test measures 4 metrics
      1. SW Enq Offload Cost: Software only enqueue offload cost, the cycle counts and time (us) from the point the enqueue API is called until the point the operation is put on the accelerator queue.
      2. Acc Enq Offload Cost: The cycle count and time (us) from the point the operation is put on the accelerator queue until the return from enqueue.
      3. SW Deq Offload Cost: Software dequeue cost, the cycle counts and time (us) consumed to dequeue one operation.
      4. Empty Queue Enq Offload Cost: The cycle count and time (us) consumed to dequeue from an empty queue.
  • Latency measurement [-c latency]
    • Measures the time consumed from the first enqueue until the first appearance of a dequeued result
    • This measurement represents the full latency of a bbdev operation (encode or decode) to execute
  • Poll-mode Throughput measurement [-c throughput]
    • Performs full operation of enqueue and dequeue
    • Executes in poll mode
    • Measures the achieved throughput on a subset or all available CPU cores
    • Dequeued data is not validated against expected values stored in TV
    • Results are printed in million operations per second and million bits per second
  • BLER measurement [-c bler]
    • Performs full operation of enqueue and dequeue
    • Measures the achieved throughput on a subset or all available CPU cores
    • Computed BLER (Block Error Rate, ratio of blocks not decoded at a given SNR) in % based on the total number of operations.
  • Interrupt-mode Throughput [-c interrupt]
    • Similar to Throughput test case, but using interrupts. No polling.

7.1.3. Parameter Globbing

Thanks to the globbing functionality in python test-bbdev.py script allows to run tests with different set of vector files without giving all of them explicitly.

Example usage for 4G:

./test-bbdev.py -v app/test-bbdev/test_vectors/turbo_<enc/dec>_c<c>_k<k>_r<r>_e<e>_<extra-info>.data

It runs all tests with following vectors:

  • bbdev_null.data
  • turbo_dec_c1_k6144_r0_e34560_sbd_negllr.data
  • turbo_enc_c1_k40_r0_e1196_rm.data
  • turbo_enc_c2_k5952_r0_e17868_crc24b.data
  • turbo_dec_c1_k40_r0_e17280_sbd_negllr.data
  • turbo_dec_c1_k6144_r0_e34560_sbd_posllr.data
  • turbo_enc_c1_k40_r0_e272_rm.data
  • turbo_enc_c3_k4800_r2_e14412_crc24b.data
  • turbo_dec_c1_k6144_r0_e10376_crc24b_sbd_negllr_high_snr.data
  • turbo_dec_c2_k3136_r0_e4920_sbd_negllr_crc24b.data
  • turbo_enc_c1_k6144_r0_e120_rm_rvidx.data
  • turbo_enc_c4_k4800_r2_e14412_crc24b.data
  • turbo_dec_c1_k6144_r0_e10376_crc24b_sbd_negllr_low_snr.data
  • turbo_dec_c2_k3136_r0_e4920_sbd_negllr.data
  • turbo_enc_c1_k6144_r0_e18444.data
  • turbo_dec_c1_k6144_r0_e34560_negllr.data
  • turbo_enc_c1_k40_r0_e1190_rm.data
  • turbo_enc_c1_k6144_r0_e18448_crc24a.data
  • turbo_dec_c1_k6144_r0_e34560_posllr.data
  • turbo_enc_c1_k40_r0_e1194_rm.data
  • turbo_enc_c1_k6144_r0_e32256_crc24b_rm.data
./test-bbdev.py -v app/test-bbdev/turbo_*_default.data

It runs all tests with “default” vectors.

  • turbo_dec_default.data is a soft link to turbo_dec_c1_k6144_r0_e10376_crc24b_sbd_negllr_high_snr.data
  • turbo_enc_default.data is a soft link to turbo_enc_c1_k6144_r0_e32256_crc24b_rm.data
  • ldpc_dec_default.data is a soft link to ldpc_dec_v6563.data
  • ldpc_enc_default.data is a soft link to ldpc_enc_c1_k8148_r0_e9372_rm.data

7.2. Running Tests

All default reference test-vectors are stored in the test_vector directory below. The prefix trivially defines which type of operation is included : turbo_enc, turbo_dec, ldpc_enc, ldpc_dec. The details of the configuration are captured in the file but some vector name refer more explicitly processing specificity such as ‘HARQ’ when HARQ retransmission is used, ‘loopback’ when the data is purely read/written for external DDR, lbrm when limited buffer rate matching is expected, or crc_fail when a CRC failure is expected. They are chosen to have a good coverage across sizes and processing parameters while still keeping their number limited as part of sanity regression.

Shortened tree of isg_cid-wireless_dpdk_ae with dpdk compiled and output to the build directory:

|-- app
    |-- test-bbdev
        |-- test_vectors

|-- build
    |-- app
        |-- dpdk-test-bbdev

7.2.1. All bbdev devices

./test-bbdev.py -p ../../build/app/dpdk-test-bbdev
-v turbo_dec_default.data

It runs all available tests using the test vector filled based on turbo_dec_default.data file. By default number of operations to process on device is set to 32, timeout is set to 300s and operations enqueue/dequeue burst size is set to 32. Moreover a bbdev (baseband_null) device will be created.

7.2.2. baseband turbo_sw device

./test-bbdev.py -p ../../build/app/dpdk-test-bbdev
-e="--vdev=baseband_turbo_sw" -t 120 -c validation
-v ./test_vectors/* -n 64 -b 8 32

It runs validation test for each vector file that matches the given pattern. Number of operations to process on device is set to 64 and operations timeout is set to 120s and enqueue/dequeue burst size is set to 8 and to 32. Moreover a bbdev (baseband_turbo_sw) device will be created.

7.2.3. bbdev null device

Executing bbdev null device with bbdev_null.data helps in measuring the overhead introduced by the bbdev framework.

./test-bbdev.py -e="--vdev=baseband_null0"
-v ./test_vectors/bbdev_null.data

Note:

baseband_null device does not have to be defined explicitly as it is created by default.

7.3. Test Vector files

Test Vector files contain the data which is used to set turbo decoder/encoder parameters and buffers for validation purpose. New test vector files should be stored in app/test-bbdev/test_vectors/ directory. Detailed description of the syntax of the test vector files is in the following section.

7.3.1. Basic principles for test vector files

Line started with # is treated as a comment and is ignored.

If variable is a chain of values, values should be separated by a comma. If assignment is split into several lines, each line (except the last one) has to be ended with a comma. There is no comma after last value in last line. Correct assignment should look like the following:

variable =
value, value, value, value,
value, value

In case where variable is a single value correct assignment looks like the following:

variable =
value

Length of chain variable is calculated by parser. Can not be defined explicitly.

Variable op_type has to be defined as a first variable in file. It specifies what type of operations will be executed. For 4G decoder op_type has to be set to RTE_BBDEV_OP_TURBO_DEC and for 4G encoder to RTE_BBDEV_OP_TURBO_ENC.

Full details of the meaning and valid values for the below fields are documented in rte_bbdev_op.h

7.3.2. Turbo decoder test vectors template

For turbo decoder it has to be always set to RTE_BBDEV_OP_TURBO_DEC

op_type =
RTE_BBDEV_OP_TURBO_DEC

Chain of uint32_t values. Note that it is possible to define more than one input/output entries which will result in chaining two or more data structures for segmented Transport Blocks

input0 =
0x00000000, 0x7f817f00, 0x7f7f8100, 0x817f8100, 0x81008100, 0x7f818100, 0x81817f00, 0x7f818100,
0x81007f00, 0x7f818100, 0x817f8100, 0x81817f00, 0x81008100, 0x817f7f00, 0x7f7f8100, 0x81817f00

Chain of uint32_t values

input1 =
0x7f7f0000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000

Chain of uint32_t values

input2 =
0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000

Chain of uint32_t values

hard_output0 =
0xa7d6732e

Chain of uint32_t values

hard_output1 =
0xa61

Chain of uint32_t values

soft_output0 =
0x817f817f, 0x7f817f7f, 0x81818181, 0x817f7f81, 0x7f818181, 0x8181817f, 0x817f817f, 0x8181817f

Chain of uint32_t values

soft_output1 =
0x817f7f81, 0x7f7f7f81, 0x7f7f8181

uint32_t value

e =
44

uint16_t value

k =
40

uint8_t value

rv_index =
0

uint8_t value

iter_max =
8

uint8_t value

iter_min =
4

uint8_t value

expected_iter_count =
8

uint8_t value

ext_scale =
15

uint8_t value

num_maps =
0

Chain of flags for LDPC decoder operation based on the rte_bbdev_op_td_flag_bitmasks:

Example:

op_flags =
RTE_BBDEV_TURBO_SUBBLOCK_DEINTERLEAVE, RTE_BBDEV_TURBO_EQUALIZER,
RTE_BBDEV_TURBO_SOFT_OUTPUT

Chain of operation statuses that are expected after operation is performed. Following statuses can be used:

  • DMA
  • FCW
  • CRC
  • OK

OK means no errors are expected. Cannot be used with other values.

expected_status =
FCW, CRC

7.3.3. Turbo encoder test vectors template

For turbo encoder it has to be always set to RTE_BBDEV_OP_TURBO_ENC

op_type =
RTE_BBDEV_OP_TURBO_ENC

Chain of uint32_t values

input0 =
0x11d2bcac, 0x4d

Chain of uint32_t values

output0 =
0xd2399179, 0x640eb999, 0x2cbaf577, 0xaf224ae2, 0x9d139927, 0xe6909b29,
0xa25b7f47, 0x2aa224ce, 0x79f2

uint32_t value

e =
272

uint16_t value

k =
40

uint16_t value

ncb =
192

uint8_t value

rv_index =
0

Chain of flags for LDPC decoder operation based on the rte_bbdev_op_te_flag_bitmasks:

RTE_BBDEV_TURBO_ENC_SCATTER_GATHER is used to indicate the parser to force the input data to be memory split and formed as a segmented mbuf.

op_flags =
RTE_BBDEV_TURBO_RATE_MATCH

Chain of operation statuses that are expected after operation is performed. Following statuses can be used:

  • DMA
  • FCW
  • OK

OK means no errors are expected. Cannot be used with other values.

expected_status =
OK

7.3.4. LDPC decoder test vectors template

For LDPC decoder it has to be always set to RTE_BBDEV_OP_LDPC_DEC

op_type =
RTE_BBDEV_OP_LDPC_DEC

Chain of uint32_t values. Note that it is possible to define more than one input/output entries which will result in chaining two or more data structures for segmented Transport Blocks

input0 =
0x00000000, 0x7f817f00, 0x7f7f8100, 0x817f8100, 0x81008100, 0x7f818100, 0x81817f00, 0x7f818100,
0x81007f00, 0x7f818100, 0x817f8100, 0x81817f00, 0x81008100, 0x817f7f00, 0x7f7f8100, 0x81817f00

output0 =
0xa7d6732e

uint8_t value

basegraph=
1

uint16_t value

z_c=
224

uint16_t value

n_cb=
14784

uint8_t value

q_m=
1

uint16_t value

n_filler=
40

uint32_t value

e=
13072

uint8_t value

rv_index=
2

uint8_t value

code_block_mode=
1

uint8_t value

iter_max=
20

uint8_t value

expected_iter_count=
8

Chain of flags for LDPC decoder operation based on the rte_bbdev_op_ldpcdec_flag_bitmasks:

Example:

op_flags =
RTE_BBDEV_LDPC_ITERATION_STOP_ENABLE, RTE_BBDEV_LDPC_HQ_COMBINE_OUT_ENABLE,
RTE_BBDEV_LDPC_HQ_COMBINE_IN_ENABLE, RTE_BBDEV_LDPC_HARQ_6BIT_COMPRESSION

Chain of operation statuses that are expected after operation is performed. Following statuses can be used:

  • OK : No error reported.
  • SYN : LDPC syndrome parity check is failing.
  • CRC : CRC parity check is failing when CRC check operation is included.
  • SYNCRC : Both CRC and LDPC syndromes parity checks are failing.

OK means no errors are expected. Cannot be used with other values.

expected_status =
CRC

7.3.5. LDPC encoder test vectors template

For turbo encoder it has to be always set to RTE_BBDEV_OP_LDPC_ENC

op_type =
RTE_BBDEV_OP_LDPC_ENC

Chain of uint32_t values

input0 =
0x11d2bcac, 0x4d

Chain of uint32_t values

output0 =
0xd2399179, 0x640eb999, 0x2cbaf577, 0xaf224ae2, 0x9d139927, 0xe6909b29,
0xa25b7f47, 0x2aa224ce, 0x79f2

uint8_t value

basegraph=
1

uint16_t value

z_c=
52

uint16_t value

n_cb=
3432

uint8_t value

q_m=
6

uint16_t value

n_filler=
0

uint32_t value

e =
1380

uint8_t value

rv_index =
1

uint8_t value

code_block_mode =
1

Chain of flags for LDPC encoder operation based on the rte_bbdev_op_ldpcenc_flag_bitmasks:

op_flags =
RTE_BBDEV_LDPC_RATE_MATCH

Chain of operation statuses that are expected after operation is performed. Following statuses can be used:

  • DMA
  • FCW
  • OK

OK means no errors are expected. Cannot be used with other values.

expected_status =
OK