xref: /openbmc/linux/Documentation/tools/rtla/common_timerlat_options.rst (revision 61273832)

**-a**, **--auto** *us*

        Set the automatic trace mode. This mode sets some commonly used options
        while debugging the system. It is equivalent to use **-T** *us* **-s** *us*
        **-t**. By default, *timerlat* tracer uses FIFO:95 for *timerlat* threads,
        thus equilavent to **-P** *f:95*.

**-p**, **--period** *us*

        Set the *timerlat* tracer period in microseconds.

**-i**, **--irq** *us*

        Stop trace if the *IRQ* latency is higher than the argument in us.

**-T**, **--thread** *us*

        Stop trace if the *Thread* latency is higher than the argument in us.

**-s**, **--stack** *us*

        Save the stack trace at the *IRQ* if a *Thread* latency is higher than the
        argument in us.

**--dma-latency** *us*
        Set the /dev/cpu_dma_latency to *us*, aiming to bound exit from idle latencies.
        *cyclictest* sets this value to *0* by default, use **--dma-latency** *0* to have
        similar results.

**-u**, **--user-threads**

        Set timerlat to run without a workload, and then dispatches user-space workloads
        to wait on the timerlat_fd. Once the workload is awakes, it goes to sleep again
        adding so the measurement for the kernel-to-user and user-to-kernel to the tracer
        output.