course updates

course/content/operating-systems/linux/monitoring/cpu/.test/multithread-cpu.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+# Function to simulate CPU usage
+simulate_cpu_usage() {
+  periodInSeconds=$1
+  core=$2
+  echo "Simulating CPU usage for $periodInSeconds seconds on core $core..."
+  end=$((SECONDS + $periodInSeconds))
+  while [ $SECONDS -lt $end ]; do
+    # Perform a CPU-intensive task directly in the script
+    for i in {1..10000}; do
+      : # No-op command, just to keep the CPU busy
+    done
+  done
+  echo "CPU usage simulation complete on core $core."
+}
+
+# Number of CPU cores
+num_cores=$(nproc)
+
+# Duration for the simulation
+duration=500
+
+# Run the function in the background for each core
+for core in $(seq 1 $num_cores); do
+  simulate_cpu_usage $duration $core &
+done
+
+# Wait for all background jobs to complete
+wait

course/content/operating-systems/linux/monitoring/cpu/.test/singlethread-cpu.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+# Function to simulate CPU usage
+simulate_cpu_usage() {
+  periodInSeconds=$1
+  echo "Simulating CPU usage for $periodInSeconds seconds..."
+  end=$((SECONDS + $periodInSeconds))
+  while [ $SECONDS -lt $end ]; do
+    # Perform a CPU-intensive task directly in the script
+    for i in {1..10000}; do
+      : # No-op command, just to keep the CPU busy
+    done
+  done
+  echo "CPU usage simulation complete."
+}
+
+# Call the function with the provided duration
+simulate_cpu_usage 500
+
+
+#ps -o pid,ppid,cmd --forest -p <PID>

course/content/operating-systems/linux/monitoring/cpu/README.md

@@ -115,13 +115,13 @@ We can take a look at two bash scripts that I have written that demonstrates sin
 
 #### example: single threaded code
 
-If we execute `./singlethread-cpu.sh`, we will notice that only one core of the CPU is busy at a time. </br>
+If we execute [./singlethread-cpu.sh](.test/singlethread-cpu.sh), we will notice that only one core of the CPU is busy at a time. </br>
 Now because we execute a loop, each iteration of that loop will run on a different core. </br>
 Bash itself is single threaded, so this script needs to be optimized if we want to make use of all available CPU cores. </br>
 
 #### example: multi threaded code 
 
-If we execute `./multithread-cpu.sh`, we will notice all CPU cores get busy. </br>
+If we execute [./multithread-cpu.sh](.test/multithread-cpu.sh), we will notice all CPU cores get busy. </br>
 This is because in this script, we read the number of available cores with the `nproc` command. </br>
 Then we loop the number of available cores and execute our `simulate_cpu_usage()` function. </br>
 At this point it would technically still be single threaded, because it's still a loop and does not create more threads or processes. </br> To get around this we use a special character in bash called `&` at the end of our function. </br>