scripts/tracetool/backend/ftrace.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 """
   5 Ftrace built-in backend.
   6 """
   7
   8 __author__     = "Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>"
   9 __copyright__  = "Copyright (C) 2013 Hitachi, Ltd."
  10 __license__    = "GPL version 2 or (at your option) any later version"
  11
  12 __maintainer__ = "Stefan Hajnoczi"
  13 __email__      = "stefanha@redhat.com"
  14
  15
  16 from tracetool import out
  17
  18
  19 PUBLIC = True
  20
  21
  22 def generate_h_begin(events, group):
  23     out('#include "trace/ftrace.h"',
  24         '')
  25
  26
  27 def generate_h(event, group):
  28     argnames = ", ".join(event.args.names())
  29     if len(event.args) > 0:
  30         argnames = ", " + argnames
  31
  32     out('        {',
  33         '            char ftrace_buf[MAX_TRACE_STRLEN];',
  34         '            int unused __attribute__ ((unused));',
  35         '            int trlen;',
  36         '            if (trace_event_get_state(%(event_id)s)) {',
  37         '                trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
  38         '                                 "%(name)s " %(fmt)s "\\n" %(argnames)s);',
  39         '                trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
  40         '                unused = write(trace_marker_fd, ftrace_buf, trlen);',
  41         '            }',
  42         '        }',
  43         name=event.name,
  44         args=event.args,
  45         event_id="TRACE_" + event.name.upper(),
  46         fmt=event.fmt.rstrip("\n"),
  47         argnames=argnames)