Hide ftrace behind a flag so it is disabled by default
We were spending like 10% CPU formatting all the Fetch and Watch
and Send messages for the kernel. Hide those behind a flag so the
default configuration is a lot quieter.
Change-Id: I58a313e27b8ebe41775af76b1529be8d1f258e5c
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/aos/ftrace.cc b/aos/ftrace.cc
index f159a76..0afbcf5 100644
--- a/aos/ftrace.cc
+++ b/aos/ftrace.cc
@@ -3,8 +3,20 @@
#include <cstdarg>
#include <cstdio>
+DEFINE_bool(
+ enable_ftrace, false,
+ "If false, disable logging to /sys/kernel/debug/tracing/trace_marker");
+
namespace aos {
+Ftrace::Ftrace()
+ : message_fd_(FLAGS_enable_ftrace
+ ? open("/sys/kernel/debug/tracing/trace_marker", O_WRONLY)
+ : -1),
+ on_fd_(FLAGS_enable_ftrace
+ ? open("/sys/kernel/debug/tracing/tracing_on", O_WRONLY)
+ : -1) {}
+
Ftrace::~Ftrace() {
if (message_fd_ != -1) {
PCHECK(close(message_fd_) == 0);