[for-next][PATCH 11/11] Documentation: Add tools/rtla timerlat -u option documentation

Steven Rostedt
2023-06-13T22:09:04Z

Add the -u/--user-thread option documentation for timerlat top/hist.

Link: https://lkml.kernel.org/r/bf727c8ccb8f50792200ae620141e047edf4af7a.1686066600.git.bristot@kernel.org

Cc: William White <chwhite@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
Documentation/tools/rtla/common_timerlat_options.rst | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/Documentation/tools/rtla/common_timerlat_options.rst b/Documentation/tools/rtla/common_timerlat_options.rst
index bacdea6de7a3..88506b397c2d 100644
--- a/Documentation/tools/rtla/common_timerlat_options.rst
+++ b/Documentation/tools/rtla/common_timerlat_options.rst
@@ -26,3 +26,10 @@
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.
--
2.39.2