• Use the below command to check a timer with clock name CLOCK_HOST_REALTIME (Just for Arm V7 SoC):
$ clocktest –C 32
2. The interrupts handled by Cobalt : IFC and e1000e interrupts are handled by the Cobalt kernel.
$ cat /proc/xenomai/irq
For e1000e test case, the Linux kernel standard network stack is used instead of rtnet stack.
NOTE
3. Cobalt IPIPE tracer: The following options are available while configuring the kernel settings:
a. CONFIG_IPIPE_TRACE_ENABLE (Enable tracing on boot): Defines if the tracer is active by default when booting
the system or shall be later enabled via
/proc/ipipe/trace/enable
. Specifically if function tracing is enabled,
deferring to switch on the tracer reduces the boot time on low-end systems.
b. CONFIG_IPIPE_TRACE_MCOUNT (Instrument function entries): Traces each entry of a kernel function. Note that
this instrumentation, though it is the most valuable one, has a significant performance impact on low-end systems
(~50% larger worst-case latencies on a Pentium-I 133 MHz).
c. CONFIG_IPIPE_TRACE_IRQSOFF (Trace IRQs-off times): Instruments each disable and re-enable of hardware
IRQs. This allows to identify the longest path in a system with IRQs disabled.
d. CONFIG_IPIPE_TRACE_SHIFT (Depth of trace log): Controls the number of trace points. The I-pipe tracer
maintains four ring buffers per CPU of the given capacity in order to switch traces in a lock-less fashion with respect
to potentially pending output requests on those buffers. If you run short on memory, try reducing the trace log depth
which is set to 16000 trace points by default.
e. CONFIG_IPIPE_TRACE_VMALLOC (Use vmalloc’ed trace buffer): Instead of reserving static kernel data, the
required buffer is allocated via
vmalloc
during boot-up when this option is enabled. This can help to start systems
that are low on memory, but it slightly degrades overall performance. Try this option when a traced kernel hangs
unexpectedly at boot time.
4. Latency of timer IRQ
$ latency -t 2 -T 60
The location of 'latency' might differ from version to version. Currently it is located in
/usr/bin
.
NOTE
5. Latency of task in Linux kernel
$ latency -t 1 -T 60
6. Latency of task in user space
$ latency -t 0 -T 60
7. Smokey to check feature enabled
$ smokey --run
8. Thread context switch
$ switchtest -T 30
NXP Semiconductors
Industrial features
Open Industrial User Guide, Rev. 1.8, 05/2020
User's Guide
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