[bootlin/training-materials updates] master: labs: debugging: remove non working lab on irq latencies (c4025403)

Clément Léger clement.leger at bootlin.com
Tue Feb 21 09:53:26 CET 2023

Repository : https://github.com/bootlin/training-materials
On branch  : master
Link       : https://github.com/bootlin/training-materials/commit/c40254039d8c481b91784d63964b0d9c7a4970db


commit c40254039d8c481b91784d63964b0d9c7a4970db
Author: Clément Léger <clement.leger at bootlin.com>
Date:   Tue Feb 21 09:53:26 2023 +0100

    labs: debugging: remove non working lab on irq latencies
    Signed-off-by: Clément Léger <clement.leger at bootlin.com>


 .../debugging-system-wide-profiling.tex            | 28 +++-------------------
 .../debugging-system-wide-profiling.tex            |  1 -
 2 files changed, 3 insertions(+), 26 deletions(-)

diff --git a/labs/debugging-system-wide-profiling/debugging-system-wide-profiling.tex b/labs/debugging-system-wide-profiling/debugging-system-wide-profiling.tex
index b3520c19..e13bae4c 100644
--- a/labs/debugging-system-wide-profiling/debugging-system-wide-profiling.tex
+++ b/labs/debugging-system-wide-profiling/debugging-system-wide-profiling.tex
@@ -2,35 +2,13 @@
 {System wide profiling and tracing}
-    \item IRQ latencies using {\em ftrace}.
-    \item Tracing and visualizing system activity using {\em kernelshark} or
-          {\em LTTng}
+    \item System profiling with {\em trace-cmd} and {\em kernelshark}.
+    \item Tracing and visualizing system activity using {\em LTTng} and
+          {\em trace-compass}.
     \item System profiling with {\em perf}.
-\section{IRQ latencies using {\em ftrace}}
-{\em ftrace} features a specific tracer for irq latency which is named irqsoff.
-Using this tracer, analyze the system irqs latency. Run the following command
-for a few seconds and hit \code{Ctrl + [C]} to stop it.
-$ trace-cmd record -p irqsoff
-Once done, you can visualize which section of code generated too much latency by
-$ trace-cmd report
-This will display a trace of the longest chain of calls while interrupts were
-disabled. Based on this report, can you find the code that generates this
-latency ?
 \section{ftrace \& uprobes}
 First of all, we will start a small program using the following command:
diff --git a/slides/debugging-system-wide-profiling/debugging-system-wide-profiling.tex b/slides/debugging-system-wide-profiling/debugging-system-wide-profiling.tex
index 98b8c289..fb73b364 100644
--- a/slides/debugging-system-wide-profiling/debugging-system-wide-profiling.tex
+++ b/slides/debugging-system-wide-profiling/debugging-system-wide-profiling.tex
@@ -1264,7 +1264,6 @@ $ lttng create my-session --set-url=net://remote-system
   Profiling a system from userspace to kernel space
-    \item Finding the longest code section with interrupt disabled
     \item Profiling with ftrace, uprobes and kernelshark
     \item Profiling with LTTng and trace-compass
     \item Profiling with perf

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