This is a note to let you know that I've just added the patch titled
rtla/hwnoise: Reduce runtime to 75%
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rtla-hwnoise-reduce-runtime-to-75.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit dd9ea04419dd9d3dedf0b5630efd45dd59231de1
Author: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Date: Tue Jun 6 18:12:22 2023 +0200
rtla/hwnoise: Reduce runtime to 75%
[ 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.1686066600.git.bristot@xxxxxxxxxx
Cc: William White <chwhite@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Tested-by: Juri Lelli <juri.lelli@xxxxxxxxxx>
Fixes: 1f428356c38d ("rtla: Add hwnoise tool")
Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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[] = {
