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):
  23     out('#include "trace/ftrace.h"',
  24         '#include "trace/control.h"',
  25         '')
  26
  27
  28 def generate_h(event):
  29     argnames = ", ".join(event.args.names())
  30     if len(event.args) > 0:
  31         argnames = ", " + argnames
  32
  33     out('    {',
  34         '        char ftrace_buf[MAX_TRACE_STRLEN];',
  35         '        int unused __attribute__ ((unused));',
  36         '        int trlen;',
  37         '        if (trace_event_get_state(%(event_id)s)) {',
  38         '            trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
  39         '                             "%(name)s " %(fmt)s "\\n" %(argnames)s);',
  40         '            trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
  41         '            unused = write(trace_marker_fd, ftrace_buf, trlen);',
  42         '        }',
  43         '    }',
  44         name=event.name,
  45         args=event.args,
  46         event_id="TRACE_" + event.name.upper(),
  47         fmt=event.fmt.rstrip("\n"),
  48         argnames=argnames)