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Commit 6591b493 authored by Josh Triplett's avatar Josh Triplett Committed by Steven Rostedt
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tracing: Add vim script to enable folding for function_graph traces 



function_graph traces look like nested function calls, complete with
braces denoting the start and end of functions.  function-graph-fold.vim
teaches vim how to fold these functions, to make it more convenient to
browse them.

To use, :source function-graph-fold.vim while viewing a function_graph
trace, or use "view -S function-graph-fold.vim some-trace" to load it
from the command-line together with a trace.  You can then use the usual
vim fold commands, such as "za", to open and close nested functions.
While closed, a fold will show the total time taken for a call, as would
normally appear on the line with the closing brace.  Folded functions
will not include finish_task_switch(), so folding should remain
relatively sane even through a context switch.

Note that this will almost certainly only work well with a single-CPU
trace (e.g. trace-cmd report --cpu 1).  It also takes some time to run
(a few seconds for a large trace on my laptop).  Nevertheless, I found
it very handy to get an overview of a trace and then drill down on
problematic calls.

Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
LKML-Reference: <20090806145701.GB7661@feather>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent f0693c8b

Documentation/trace/function-graph-fold.vim

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+42 −0
Original line number Diff line number Diff line 
" Enable folding for ftrace function_graph traces.

"

" To use, :source this file while viewing a function_graph trace, or use vim's

" -S option to load from the command-line together with a trace.  You can then

" use the usual vim fold commands, such as "za", to open and close nested

" functions.  While closed, a fold will show the total time taken for a call,

" as would normally appear on the line with the closing brace.  Folded

" functions will not include finish_task_switch(), so folding should remain

" relatively sane even through a context switch.

"

" Note that this will almost certainly only work well with a

" single-CPU trace (e.g. trace-cmd report --cpu 1).



function! FunctionGraphFoldExpr(lnum)

  let line = getline(a:lnum)

  if line[-1:] == '{'

    if line =~ 'finish_task_switch() {$'

      return '>1'

    endif

    return 'a1'

  elseif line[-1:] == '}'

    return 's1'

  else

    return '='

  endif

endfunction



function! FunctionGraphFoldText()

  let s = split(getline(v:foldstart), '|', 1)

  if getline(v:foldend+1) =~ 'finish_task_switch() {$'

    let s[2] = ' task switch  '

  else

    let e = split(getline(v:foldend), '|', 1)

    let s[2] = e[2]

  endif

  return join(s, '|')

endfunction



setlocal foldexpr=FunctionGraphFoldExpr(v:lnum)

setlocal foldtext=FunctionGraphFoldText()

setlocal foldcolumn=12

setlocal foldmethod=expr