qemu-e2k/scripts/tracetool/backend/ftrace.py
Lluís Vilanova 40b9cd25f7 trace: Conditionally trace events based on their per-vCPU state
Events with the 'vcpu' property are conditionally emitted according to
their per-vCPU state. Other events are emitted normally based on their
global tracing state.

Note that the per-vCPU condition check applies to all tracing backends.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-18 18:23:12 +01:00

49 lines
1.4 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Ftrace built-in backend.
"""
__author__ = "Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>"
__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 generate_h_begin(events):
out('#include "trace/ftrace.h"',
'#include "trace/control.h"',
'')
def generate_h(event):
argnames = ", ".join(event.args.names())
if len(event.args) > 0:
argnames = ", " + argnames
out(' {',
' char ftrace_buf[MAX_TRACE_STRLEN];',
' int unused __attribute__ ((unused));',
' int trlen;',
' if (trace_event_get_state(%(event_id)s)) {',
' 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=event.name,
args=event.args,
event_id="TRACE_" + event.name.upper(),
fmt=event.fmt.rstrip("\n"),
argnames=argnames)