is-cpu-isolated: Keep an eye on all possible interrupts

Until now we were only concerned about interruption from ticks and so were
checking only interrupts from arch_timer.

But there are few problems here:

- To check which row belongs to tick-timer, we need to grep for a string. It can
  be "arch-timer", "twd", "NMI", etc for different platforms and so the script
  was never generic.

- Also, interruption is possible from other peripherals, PPI, SPI, IPC, etc

This patch adds in another AWK script to get total number of interrupts for any
CPU (though it supports returning that for all CPUs at once, its not used
currently). We use this instead of looking at tick-timer.

Change-Id: I2aab004314459a928e5ebc505d03a4525957c40e
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

1 files changed, 62 insertions, 9 deletions

diff --git a/common/scripts/is-cpu-isolated.sh b/common/scripts/is-cpu-isolated.sh
index d749582..7984fb5 100755
--- a/common/scripts/is-cpu-isolated.sh
+++ b/common/scripts/is-cpu-isolated.sh
@@ -35,11 +35,50 @@ isdebug() {
 	fi
 }
 
-# routine to get tick count: Expects all CPUs to be online (otherwise column
-# number may get wrong)
-get_tick_count() { cat /proc/interrupts | grep arch_timer | grep 30 | sed 's/\s\+/ /g' | sed 's/^\s//g' | cut -d' ' -f$((2+$ISOL_CPU)) ; }
-#For testing script on: x86
-#get_tick_count() { cat /proc/interrupts | grep NMI | sed 's/\s\+/ /g' | sed 's/\s\+/ /g' | cut -d' ' -f$((2+$ISOL_CPU)) ; }
+# Find total number of interrupts for
+# - one CPU, pass cpu number as parameter
+# - all CPUs, pass "ALL" as parameter
+total_interrupts() {
+	awk -v isolate_cpu="$1" '
+	BEGIN {
+		line=0;
+	}
+
+	# Find total CPUs, do only on first row
+	NR==1 {
+		cpus = NF;
+		next;
+	}
+
+	# Fill array with interrupt counts
+	{
+		for (cpu = 0; cpu < cpus; cpu++) {
+			irqs[cpu, line] = $(cpu+2);
+		}
+		line++;
+	}
+
+	# Count total interrupts:
+	END {
+		for (cpu = 0; cpu < cpus; cpu++) {
+			for (j = 0; j < line; j++) {
+				count[cpu] += irqs[cpu,j];
+				# for debugging
+				# printf "%d: %d: %d\n",cpu, j,irqs[cpu,j];
+			}
+
+			if (isolate_cpu == "ALL")
+				printf "%d ",count[cpu]
+			else if (cpu == isolate_cpu)
+				printf "%d ",count[cpu]
+
+		}
+		printf "\n"
+	}
+
+	# File to process
+' /proc/interrupts
+}
 
 # update list of all non-ISOL CPUs
 update_non_isol_cpus() {
@@ -173,6 +212,14 @@ isolate_cpu() {
 	done
 }
 
+dump_interrupts() {
+	[ ! $1 ] && printf "\n\nInitial dump of /proc/interrupts\n"
+	[ $1 ] && printf "\n\nInterrupted: new dump of /proc/interrupts\n"
+
+	cat /proc/interrupts
+	printf "\n\n"
+}
+
 # routine to get CPU isolation time
 get_isolation_duration() {
 	isdebug echo ""
@@ -183,14 +230,17 @@ get_isolation_duration() {
 	isdebug echo "No. of samples requested:" $SAMPLE_COUNT", min isolation required:" $MIN_ISOLATION
 	isdebug echo ""
 
-	new_count=$(get_tick_count)
+	isdebug dump_interrupts
+
+	# Get initial count
+	new_count=$(total_interrupts $ISOL_CPU)
 	isdebug echo "initial count: " $new_count
 
 	old_count=$new_count
 	T2="$(date +%s)"
 	while [ $new_count -eq $old_count ]
 	do
-		new_count=$(get_tick_count)
+		new_count=$(total_interrupts $ISOL_CPU)
 		ps h -C stress -o pid > /dev/null
 		if [ $? != 0 ]; then
 			T=$(($(date +%s)-$T2))
@@ -214,6 +264,9 @@ get_isolation_duration() {
 	do
 		let x=x+1
 
+		# Interrupted, dump interrupts
+		isdebug dump_interrupts 1
+
 		T1=$T2
 		isdebug echo "Start Time in seconds: ${T1}"
 
@@ -221,14 +274,14 @@ get_isolation_duration() {
 		sleep .1
 
 		# get count again after continuous ticks are skiped
-		old_count=$(get_tick_count)
+		old_count=$(total_interrupts $ISOL_CPU)
 		new_count=$old_count
 
 
 		T2="$(date +%s)"
 		while [ $new_count -eq $old_count ]
 		do
-			new_count=$(get_tick_count)
+			new_count=$(total_interrupts $ISOL_CPU)
 			ps h -C stress -o pid > /dev/null
 			if [ $? != 0 ]; then
 				T=$(($(date +%s)-$T2))