Description

This escript converts erlang's fprof output to valgrind's callgrind output.

To generate the fprof output use fprof:analyse({dest, "outfile.fprof"}).. Do not use totals.

Converting to callgrind is simple, just type: ./erlgrind_script outfile.fprof outfile.cgrind.

You must have escript in your PATH.

Then you can open outfile.cgrind with a tool like kcachegrind.

Formats

For a description of fprof's format, check fprof.

For a description of callgrind's format, check callgrind.

Usage

Usage: erlgring [Options] <input file .trace/.analysis> [<output file>]
Options:
    -p	use process pid as ELF object
	-h	show this message

If you use a file with a .trace extension, erlgrind will treat it as a file generated with fprof:trace, automatically analyse it with fprof:analyse and proceed with the conversion. The output file name is optional.

Example

The fprof output:

%% Analysis results:
{  analysis_options,
 [{callers, true},
  {sort, acc},
  {totals, false},
  {details, true}]}.

%                                               CNT       ACC       OWN        
[{ totals,                                       90,    0.330,    0.330}].  %%%


%                                               CNT       ACC       OWN        
[{ "<0.33.0>",                                   90,undefined,    0.330}].   %%

{[{{sort,quicksort,1},                            0,    0.269,    0.007},      
  {undefined,                                     0,    0.025,    0.018},      
  {{fprof,call,1},                                1,    0.018,    0.014}],     
 { {fprof,just_call,2},                           1,    0.312,    0.039},     %
 [{{sort,quicksort_div,4},                        1,    0.262,    0.004},      
  {{erlang,demonitor,1},                          1,    0.007,    0.007},      
  {{erlang,monitor,2},                            1,    0.004,    0.004},      
  {suspend,                                       1,    0.000,    0.000}]}.    

{[{undefined,                                     0,    0.269,    0.000},      
  {{erl_eval,do_apply,5},                         0,    0.036,    0.003}],     
 { {sort,quicksort,1},                            0,    0.305,    0.003},     %
 [{{fprof,just_call,2},                           0,    0.269,    0.007},      
  {{fprof,trace,1},                               1,    0.033,    0.004}]}.    

{[{{fprof,just_call,2},                           1,    0.262,    0.004},      
  {{sort,quicksort_div,4},                       64,    0.000,    0.185}],     
 { {sort,quicksort_div,4},                       65,    0.262,    0.189},     %
 [{{sort,merge,3},                                9,    0.073,    0.050},      
  {{sort,quicksort_div,4},                       64,    0.000,    0.185}]}.    

{[{{sort,quicksort_div,4},                        9,    0.073,    0.050}],     
 { {sort,merge,3},                                9,    0.073,    0.050},     %
 [{{erlang,'++',2},                               9,    0.023,    0.023}]}.    
 

Will generate the callgrind output:

events: Time
summary: 330
ob=<0.33.0>
fl=fprof
fn={fprof,just_call,2}
1 39
cfl=sort
cfn={sort,quicksort_div,4}
calls=1 1
1 262
cfl=erlang
cfn={erlang,demonitor,1}
calls=1 1
1 7
cfl=erlang
cfn={erlang,monitor,2}
calls=1 1
1 4
cfl=pseudo
cfn=suspend
calls=1 1
1 0
fl=sort
fn={sort,quicksort,1}
1 3
cfl=fprof
cfn={fprof,just_call,2}
calls=0 1
1 269
cfl=fprof
cfn={fprof,trace,1}
calls=1 1
1 33
fl=sort
fn={sort,quicksort_div,4}
1 189
cfl=sort
cfn={sort,merge,3}
calls=9 1
1 73
cfl=sort
cfn={sort,quicksort_div,4}
calls=64 1
1 0
fl=sort
fn={sort,merge,3}
1 50
cfl=erlang
cfn={erlang,'++',2}
calls=9 1
1 23
fl=erl_eval
fn={erl_eval,do_apply,5}
1 0
cfl=sort
cfn={sort,quicksort,1}
calls=0 1
1 36
fl=fprof
fn={fprof,trace,1}
1 4
cfl=fprof
cfn={fprof,call,1}
calls=1 1
1 29
fl=fprof
fn={fprof,call,1}
1 7
cfl=fprof
cfn={fprof,just_call,2}
calls=1 1
1 18
cfl=erlang
cfn={erlang,whereis,1}
calls=1 1
1 4
fl=erlang
fn={erlang,'++',2}
1 23

Where:

• costs are in milliseconds
• ob is set as the Pid of the process that called the function
• file is set as the erlang module
• line numbers are hardcoded as 1