forked from Minki/linux
7d0dc9576d
Add the --dma-latency to set /dev/cpu_dma_latency to the specified value, this aims to avoid having exit from idle states latencies that could be influencing the analysis. Link: https://lkml.kernel.org/r/72ddb0d913459f13217086dadafad88a7c46dd28.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Clark Williams <williams@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
29 lines
967 B
ReStructuredText
29 lines
967 B
ReStructuredText
**-a**, **--auto** *us*
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Set the automatic trace mode. This mode sets some commonly used options
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while debugging the system. It is equivalent to use **-T** *us* **-s** *us*
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**-t**. By default, *timerlat* tracer uses FIFO:95 for *timerlat* threads,
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thus equilavent to **-P** *f:95*.
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**-p**, **--period** *us*
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Set the *timerlat* tracer period in microseconds.
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**-i**, **--irq** *us*
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Stop trace if the *IRQ* latency is higher than the argument in us.
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**-T**, **--thread** *us*
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Stop trace if the *Thread* latency is higher than the argument in us.
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**-s**, **--stack** *us*
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Save the stack trace at the *IRQ* if a *Thread* latency is higher than the
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argument in us.
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**--dma-latency** *us*
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Set the /dev/cpu_dma_latency to *us*, aiming to bound exit from idle latencies.
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*cyclictest* sets this value to *0* by default, use **--dma-latency** *0* to have
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similar results.
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