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 c(events):
  23     pass
  24
  25 def h(events):
  26     out('#include "trace/ftrace.h"',
  27         '#include "trace/control.h"',
  28         '',
  29         )
  30
  31     for e in events:
  32         argnames = ", ".join(e.args.names())
  33         if len(e.args) > 0:
  34             argnames = ", " + argnames
  35
  36         out('static inline void trace_%(name)s(%(args)s)',
  37             '{',
  38             '    char ftrace_buf[MAX_TRACE_STRLEN];',
  39             '    int unused __attribute__ ((unused));',
  40             '    int trlen;',
  41             '    bool _state = trace_event_get_state(%(event_id)s);',
  42             '    if (_state) {',
  43             '        trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
  44             '                         "%(name)s " %(fmt)s "\\n" %(argnames)s);',
  45             '        trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
  46             '        unused = write(trace_marker_fd, ftrace_buf, trlen);',
  47             '    }',
  48             '}',
  49             name = e.name,
  50             args = e.args,
  51             event_id = "TRACE_" + e.name.upper(),
  52             fmt = e.fmt.rstrip("\n"),
  53             argnames = argnames,
  54             )