255. Sample Application Tests: Timer Example

This example shows how timer can be used in a RTE application. This program print some messages from different lcores regularly, demonstrating how to use timers.

If using vfio the kernel must be >= 3.6+ and VT-d must be enabled in bios.When using vfio, use the following commands to load the vfio driver and bind it to the device under test:

modprobe vfio
modprobe vfio-pci
usertools/dpdk-devbind.py --bind=vfio-pci device_bus_id

In the timer example there are two timers.

Timer 0 is periodical, running on the master lcore, reloaded automatically every second.

Timer 1 is single one, being loaded manually by every second/3 , once manually load will switch to next lcore.

Usage of application:

./timer [EAL options]

Where the EAL options are:

EAL option list:
  -c COREMASK: hexadecimal bitmask of cores we are running on
  -m MB      : memory to allocate (default = size of hugemem)
  -n NUM     : force number of memory channels (don't detect)
  -r NUM     : force number of memory ranks (don't detect)
  --huge-file: base filename for hugetlbfs entries
debug options:
  --no-huge  : use malloc instead of hugetlbfs
  --no-pci   : disable pci
  --no-hpet  : disable hpet
  --no-shconf: no shared config (mmap'd files)

255.1. Prerequisites

To find out the mapping of lcores (processor) to core id and socket (physical id), the command below can be used:

$ grep "processor\|physical id\|core id\|^$" /proc/cpuinfo

The number of logical core will be used as parameter to the timer example.

255.2. Test Case: timer callbacks running on targeted cores

To run the example in linuxapp environment:

./timer -c ffffff

Timer0, every second, on master lcore, reloaded automatically. The check output as below by every second on master lcore:

timer0_cb() on lcore 0

Timer1, every second/3, on next lcore, reloaded manually. The check output as below by every second/3 on master lcore:

timer1_cb() on lcore 1
timer1_cb() on lcore 2
timer1_cb() on lcore 3
timer1_cb() on lcore 4
timer1_cb() on lcore 23

Verify the timer0_cb and timer1_cb care called properly on the target cores.