From 781e9545dbe54d2f0a530edbf48fd0ac1e77244c Mon Sep 17 00:00:00 2001 From: Eiichi Tsukata Date: Thu, 11 Apr 2013 20:25:15 +0900 Subject: trace: Add ftrace tracing backend This patch adds a ftrace tracing backend which sends trace event to ftrace marker file. You can effectively compare qemu trace data and kernel(especially, kvm.ko when using KVM) trace data. The ftrace backend is restricted to Linux only. To try out the ftrace backend: $ ./configure --trace-backend=ftrace $ make if you use KVM, enable kvm events in ftrace: # sudo echo 1 > /sys/kernel/debug/tracing/events/kvm/enable After running qemu by root user, you can get the trace: # cat /sys/kernel/debug/tracing/trace Signed-off-by: Eiichi Tsukata Signed-off-by: Stefan Hajnoczi --- scripts/tracetool/backend/ftrace.py | 54 +++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 scripts/tracetool/backend/ftrace.py (limited to 'scripts/tracetool') diff --git a/scripts/tracetool/backend/ftrace.py b/scripts/tracetool/backend/ftrace.py new file mode 100644 index 0000000..888c361 --- /dev/null +++ b/scripts/tracetool/backend/ftrace.py @@ -0,0 +1,54 @@ +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +""" +Ftrace built-in backend. +""" + +__author__ = "Eiichi Tsukata " +__copyright__ = "Copyright (C) 2013 Hitachi, Ltd." +__license__ = "GPL version 2 or (at your option) any later version" + +__maintainer__ = "Stefan Hajnoczi" +__email__ = "stefanha@redhat.com" + + +from tracetool import out + + +PUBLIC = True + + +def c(events): + pass + +def h(events): + out('#include "trace/ftrace.h"', + '#include "trace/control.h"', + '', + ) + + for e in events: + argnames = ", ".join(e.args.names()) + if len(e.args) > 0: + argnames = ", " + argnames + + out('static inline void trace_%(name)s(%(args)s)', + '{', + ' char ftrace_buf[MAX_TRACE_STRLEN];', + ' int unused __attribute__ ((unused));', + ' int trlen;', + ' bool _state = trace_event_get_state(%(event_id)s);', + ' if (_state) {', + ' trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,', + ' "%(name)s " %(fmt)s "\\n" %(argnames)s);', + ' trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);', + ' unused = write(trace_marker_fd, ftrace_buf, trlen);', + ' }', + '}', + name = e.name, + args = e.args, + event_id = "TRACE_" + e.name.upper(), + fmt = e.fmt.rstrip("\n"), + argnames = argnames, + ) -- cgit v1.1