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| author | Daniel Bristot de Oliveira <bristot@kernel.org> | 2022-03-02 20:01:39 +0100 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-03-15 14:36:50 -0400 |
| commit | 7d0dc9576dc3817c483b408715e506c3e9f37bed (patch) | |
| tree | e611e595de3762767ed6afce4c565c5b5a566d3c /Documentation/tools | |
| parent | 7d38c35167c58153e8b5bea839616d00e90564b9 (diff) | |
| download | linux-7d0dc9576dc3817c483b408715e506c3e9f37bed.tar.gz linux-7d0dc9576dc3817c483b408715e506c3e9f37bed.tar.bz2 linux-7d0dc9576dc3817c483b408715e506c3e9f37bed.zip | |
rtla/timerlat: Add --dma-latency option
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>
Diffstat (limited to 'Documentation/tools')
| -rw-r--r-- | Documentation/tools/rtla/common_timerlat_options.rst | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/tools/rtla/common_timerlat_options.rst b/Documentation/tools/rtla/common_timerlat_options.rst index 14a24a121f5d..bacdea6de7a3 100644 --- a/Documentation/tools/rtla/common_timerlat_options.rst +++ b/Documentation/tools/rtla/common_timerlat_options.rst @@ -21,3 +21,8 @@ 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. |