93. Multiple Pthread Test

93.1. Description

This test is a basic multiple pthread test which demonstrates the basics of control group. Cgroup is a Linux kernel feature that limits, accounts for and isolates the resource usage, like CPU, memory, disk I/O, network, etc of a collection of processes. Now, it’s focus on the CPU usage.

93.2. Prerequisites

Support igb_uio driver, kernel is 3.11+. Use “modprobe uio” “modprobe igb_uio” and then use ”./tools/dpdk_nic_bind.py –bind=igb_uio device_bus_id” to bind the ports.

Assuming that an Intel’s DPDK build has been set up and the testpmd applications have been built.

Os required: Linux and FreeBSD. The command used in the test plan is only for Linux OS.

The format pattern:

–lcores=’<lcore_set>[@cpu_set][,<lcore_set>[@cpu_set],...]’

‘lcore_set’ and ‘cpu_set’ can be a single number, range or a group. A number is a “digit([0-9]+)”; a range is “<number>-<number>”; a group is “(<number|range>[,<number|range>,...])”. If a ‘@cpu_set’ value is not supplied, the value of ‘cpu_set’ will default to the value of ‘lcore_set’. For example, “–lcores=‘1,2@(5-7),(3-5)@(0,2),(0,6),7-8’” which means start 9 EAL thread:

lcore 0 runs on cpuset 0x41 (cpu 0,6);
lcore 1 runs on cpuset 0x2 (cpu 1);
lcore 2 runs on cpuset 0xe0 (cpu 5,6,7);
lcore 3,4,5 runs on cpuset 0x5 (cpu 0,2);
lcore 6 runs on cpuset 0x41 (cpu 0,6);
lcore 7 runs on cpuset 0x80 (cpu 7);
lcore 8 runs on cpuset 0x100 (cpu 8).

93.3. Test Case 1: Basic operation

To run the application, start the testpmd with the lcores all running with threads and also the unique core assigned, command as follows:

./x86_64-native-linuxapp-gcc/app/testpmd --lcores='0@8,(4-5)@9' -n 4 -- -i

Using the command to make sure the lcore are init on the correct cpu:

ps -C testpmd -L -opid,tid,%cpu,psr,args

Result as follows:

PID     TID    %CPU   PSR COMMAND
31038   31038  22.5   8   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i
31038   31039  0.0    8   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i
31038   31040  0.0    9   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i
31038   31041  0.0    9   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i
31038   31042  0.0    8   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i

Their TIDs are for these threads as below:

+------------------------+
| TID   | THREAD         |
+-------+----------------+
| 31038 | Master thread  |
+-------+----------------+
| 31039 |Eal-intr-thread |
+------+-----------------+
| 31040 | Lcore-slave-4  |
+-------+----------------+
| 31041 | Lcore-slave-5  |
+-------+----------------+
| 31042 | Pdump-thread   |
+-------+----------------+

Before running the test, make sure the core is a unique one otherwise, the throughput will be floating on different cores, configure lcore 4&5 used for packet forwarding, command as follows:

testpmd>set corelist 4,5

Pay attention that set corelist need to be configured before start, otherwise, it will not work:

testpmd>start

Check forward configuration:

testpmd>show config fwd
Logical Core 4 (socket 0) forwards packets on 1 streams:
  RX P=0/Q=0 (socket 1) -> TX P=1/Q=0 (socket 1) peer=02:00:00:00:00:01
Logical Core 5 (socket 0) forwards packets on 1 streams:
  RX P=1/Q=0 (socket 1) -> TX P=0/Q=0 (socket 1) peer=02:00:00:00:00:00

Send packets continuous:

PID    TID   %CPU   PSR COMMAND
31038  31038  0.6   8   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i
31038  31039  0.0   8   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i
31038  31040  1.5   9   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i
31038  31041  1.5   9   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i
31038  31042  0.0   8   ./x86_64-native-linuxapp-gcc/app/testpmd --lcores=0@8,(4-5)@9 -n 4 -- -i

You can see TID 31040(Lcore 4), 31041(Lore 5) are running.

93.4. Test Case 2: Positive Test

Input random valid commands to make sure the commands can work, Give examples, suppose DUT have 128 cpu core.

Case 1:

./x86_64-native-linuxapp-gcc/app/testpmd --lcores='0@8,(4-5)@(8-11)' -n 4 -- -i

It means start 3 EAL thread:

lcore 0 runs on cpuset 0x100 (cpu 8);
lcore 4,5 runs on cpuset 0x780 (cpu 8,9,10,11).

Case 2:

./x86_64-native-linuxapp-gcc/app/testpmd --lcores='1,2@(0-4,6),(3-4,6)@5,(7,8)' -n 4 -- -i

It means start 7 EAL thread:

lcore 1 runs on cpuset 0x2 (cpu 1);
lcore 2 runs on cpuset 0x5f (cpu 0,1,2,3,4,6);
lcore 3,4,6 runs on cpuset 0x10 (cpu 5);
lcore 7 runs on cpuset 0x80 (cpu 7);
lcore 8 runs on cpuset 0x100 (cpu 8).

Case 3:

./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,CONFIG_RTE_MAX_LCORE-1)@(4,5)' -n 4 -- -i

(default CONFIG_RTE_MAX_LCORE=128). It means start 2 EAL thread:

lcore 0,127 runs on cpuset 0x30 (cpu 4,5).

Case 4:

./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,64-66)@(4,5)' -n 4 -- -i

It means start 4 EAL thread:

lcore 0,64,65,66 runs on cpuset 0x30 (cpu 4,5).

Case 5:

./x86_64-native-linuxapp-gcc/app/testpmd --lcores='2-5,6,7-9' -n 4 -- -i

It means start 8 EAL thread:

lcore 2 runs on cpuset 0x4 (cpu 2);
lcore 3 runs on cpuset 0x8 (cpu 3);
lcore 4 runs on cpuset 0x10 (cpu 4);
lcore 5 runs on cpuset 0x20 (cpu 5);
lcore 6 runs on cpuset 0x40 (cpu 6);
lcore 7 runs on cpuset 0x80 (cpu 7);
lcore 8 runs on cpuset 0x100 (cpu 8);
lcore 9 runs on cpuset 0x200 (cpu 9).

Case 6:

./x86_64-native-linuxapp-gcc/app/testpmd --lcores='2,(3-5)@3' -n 4 -- -i

It means start 4 EAL thread:

lcore 2 runs on cpuset 0x4 (cpu 2);
lcore 3,4,5 runs on cpuset 0x8 (cpu 3).

Case 7:

./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,7-4)@(4,5)' -n 4 -- -i

It means start 5 EAL thread:

lcore 0,4,5,6,7 runs on cpuset 0x30 (cpu 4,5)

93.5. Test Case 3: Negative Test

Input invalid commands to make sure the commands can’t work:

./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0-,4-7)@(4,5)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(-1,4-7)@(4,5)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,4-7-9)@(4,5)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,abcd)@(4,5)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,4-7)@(1-,5)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,4-7)@(-1,5)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,4-7)@(4,5-8-9)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,4-7)@(abc,5)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,4-7)@(4,xyz)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0,4-7)=(8,9)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='2,3 at 4,(0-1,,4))' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='[0-,4-7]@(4,5)' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='(0-,4-7)@[4,5]' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='3-4 at 3,2 at 5-6' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='2,,3''2--3' -n 4 -- -i
./x86_64-native-linuxapp-gcc/app/testpmd --lcores='2,,,3''2--3' -n 4 -- -i