[PATCH v2] rcutorture: Copy out ftrace into its own console file

[Joel Fernandes (Google)]

From: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>

Often times during debugging, it is difficult to jump to the ftrace dump
in the console log and treat it independent of the result of the log file.
Copy the contents of the buffers into its own file to make it easier to refer
to the ftrace dump. The original ftrace dump is still available in the
console log if it is desired to refer to it there.

Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
v1-v2: Change log updates, "From:" updates.

 .../selftests/rcutorture/bin/functions.sh     | 24 +++++++++++++++++++
 .../selftests/rcutorture/bin/parse-console.sh |  7 ++++++
 2 files changed, 31 insertions(+)
 mode change 100644 => 100755 tools/testing/selftests/rcutorture/bin/functions.sh

diff --git a/tools/testing/selftests/rcutorture/bin/functions.sh b/tools/testing/selftests/rcutorture/bin/functions.sh
old mode 100644
new mode 100755
index b8e2ea23cb3f..2ec4ab87a7f0
--- a/tools/testing/selftests/rcutorture/bin/functions.sh
+++ b/tools/testing/selftests/rcutorture/bin/functions.sh
@@ -331,3 +331,27 @@ specify_qemu_net () {
 		echo $1 -net none
 	fi
 }
+
+# Extract the ftrace output from the console log output
+# The ftrace output looks in the logs looks like:
+# Dumping ftrace buffer:
+# ---------------------------------
+# [...]
+# ---------------------------------
+extract_ftrace_from_console() {
+        awk '
+        /Dumping ftrace buffer:/ {
+        capture = 1
+        next
+    }
+    /---------------------------------/ {
+        if(capture == 1) {
+            capture = 2
+            next
+        } else if(capture == 2) {
+            capture = 0
+        }
+    }
+    capture == 2
+    ' "$1";
+}
diff --git a/tools/testing/selftests/rcutorture/bin/parse-console.sh b/tools/testing/selftests/rcutorture/bin/parse-console.sh
index 9ab0f6bc172c..e3d2f69ec0fb 100755
--- a/tools/testing/selftests/rcutorture/bin/parse-console.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-console.sh
@@ -182,3 +182,10 @@ if ! test -s $file.diags
 then
 	rm -f $file.diags
 fi
+
+# Call extract_ftrace_from_console function, if the output is empty,
+# don't create $file.ftrace. Otherwise output the results to $file.ftrace
+extract_ftrace_from_console $file > $file.ftrace
+if [ ! -s $file.ftrace ]; then
+	rm -f $file.ftrace
+fi
-- 
2.41.0.640.ga95def55d0-goog