From: Daniel Bristot de Oliveira bristot@kernel.org
[ Upstream commit 7bc4d3089a50050d4df0af63423a5d907c3bdb1a ]
osnoise runs 100% of time by default. It makes sense because osnoise is preemptive. hwnoise checks preemption once a second, so it reduces system progress.
Reduce runtime to 75% to avoid problems by default. I added a Fixes as it might avoid problems for first time users as it lands on distros.
Link: https://lkml.kernel.org/r/af0b7113ffc00031b9af4bb40ef5889a27dadf8c.168606660...
Cc: William White chwhite@redhat.com Cc: Jonathan Corbet corbet@lwn.net Tested-by: Juri Lelli juri.lelli@redhat.com Fixes: 1f428356c38d ("rtla: Add hwnoise tool") Signed-off-by: Daniel Bristot de Oliveira bristot@kernel.org Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/tracing/rtla/src/osnoise_top.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c index 562f2e4b18c57..3ece8c09ecd95 100644 --- a/tools/tracing/rtla/src/osnoise_top.c +++ b/tools/tracing/rtla/src/osnoise_top.c @@ -340,8 +340,14 @@ struct osnoise_top_params *osnoise_top_parse_args(int argc, char **argv) if (!params) exit(1);
- if (strcmp(argv[0], "hwnoise") == 0) + if (strcmp(argv[0], "hwnoise") == 0) { params->mode = MODE_HWNOISE; + /* + * Reduce CPU usage for 75% to avoid killing the system. + */ + params->runtime = 750000; + params->period = 1000000; + }
while (1) { static struct option long_options[] = {