Under some circumstances it's possible to get a divider 0 which crashes
the script.

  Traceback (most recent call last):
    File "linux/scripts/bloat-o-meter", line 98, in <module>
      print_result("Function", "tTdDbBrR", 2)
    File "linux/scripts/bloat-o-meter", line 87, in print_result
      (otot, ntot, (ntot - otot)*100.0/otot))
  ZeroDivisionError: float division by zero

Hide this by checking the divider first.

Link: http://lkml.kernel.org/r/20171123171219.31453-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch provides 3 new arguments for bloat-o-meter
 1) -c -> for all (showing function and data differently)
 2) -d -> data
 3) -t -> function

output:

  ./scripts/bloat-o-meter  -c "file1" "file2"
  add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-152 (-152)
  Function                                     old     new   delta
  main                                         412     260    -152
  Total: Before=548, After=396, chg -27.74%
  ##########################################################
  add/remove: 1/0 grow/shrink: 1/0 up/down: 84/0 (84)
  Data                                         old     new   delta
  arr                                            -      64     +64
  backtrace                                     60      80     +20
  Total: Before=109, After=193, chg +77.06%
  ##########################################################
  add/remove: 0/1 grow/shrink: 0/0 up/down: 0/-64 (-64)
  RO Data                                      old     new   delta
  arr                                           64       -     -64
  Total: Before=68, After=4, chg -94.12%

[maninder1.s@samsung.com: v1 -> v2]
  Link: http://lkml.kernel.org/r/1506569402-24787-1-git-send-email-maninder1.s@samsung.com
Link: http://lkml.kernel.org/r/1506336313-27187-1-git-send-email-maninder1.s@samsung.com
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: <pankaj.m@samsung.com>
Cc: <a.sahrawat@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Every often used regex is better be compiled in Python.

Speedup is about ~9.8% (whee!)

    $ perf stat -r 16 taskset -c 15 ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux >/dev/null
    7.091202853 seconds time elapsed                         ( +-  0.15% )

    +re.compile
    6.397564973 seconds time elapsed                         ( +-  0.34% )

Link: http://lkml.kernel.org/r/20161119004417.GB1200@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

readlines() conses whole list before doing anything which is slower for
big object files.  Use per line iterator.

Speed up is ~2% on "allyesconfig" type of kernel.

    $ perf stat -r 16 taskset -c 15 ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux >/dev/null
	...

  Before:  7.247708646 seconds time elapsed                ( +-  0.28% )
  After:   7.091202853 seconds time elapsed                ( +-  0.15% )

Link: http://lkml.kernel.org/r/20161119004143.GA1200@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix piping output to a program which quickly exits (read: head -n1)

	$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux | head -n1
	add/remove: 0/0 grow/shrink: 9/60 up/down: 124/-305 (-181)
	close failed in file object destructor:
	sys.excepthook is missing
	lost sys.stderr

Link: http://lkml.kernel.org/r/20161028204618.GA29923@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Python divisions are integer divisions unless at least one parameter is
a float.  The current bloat-o-meter fails to print sub-percentage
changes:

  Total: Before=10515408, After=10604060, chg 0.000000%

Force float division by using one float and pretty the print to two
significant decimals:

  Total: Before=10515408, After=10604060, chg +0.84%

Link: http://lkml.kernel.org/r/1465980311-23814-1-git-send-email-riku.voipio@linaro.org
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This adds an additional line of output (to reduce the chances of
breaking any existing output parsers) which prints the total size before
and after and the relative difference.

  add/remove: 39/0 grow/shrink: 12408/55 up/down: 362227/-1430 (360797)
  function                                     old     new   delta
  ext4_fill_super                            10556   12590   +2034
  _fpadd_parts                                   -    1186   +1186
  ntfs_fill_super                             5340    6164    +824
  ...
  ...
  __divdf3                                     752     386    -366
  unlzma                                      3682    3274    -408
  Total: Before=5023101, After=5383898, chg 7.000000%
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Link: http://lkml.kernel.org/r/1463124110-30314-1-git-send-email-vgupta@synopsys.com
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In Python3+ print is a function so the old syntax is not correct
anymore:

  $ ./scripts/bloat-o-meter vmlinux.o vmlinux.o.old
    File "./scripts/bloat-o-meter", line 61
      print "add/remove: %s/%s grow/shrink: %s/%s up/down: %s/%s (%s)" % \
                                                                     ^
  SyntaxError: invalid syntax

Fix by calling print as a function.

Tested on python 2.7.11, 3.5.1

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This avoids double-counting size changes in syscall implementations.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>

str.startswith has existed since at least Python 2.0, in 2000; use it
rather than a fragile comparison against an initial slice of a string,
which requires hard-coding the length of the string to compare against.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>