[arch-general] imagemagick 6.8.9.8-1 is slower than 6.8.9.7-1

[Matthew Wynn]

As shown in the forum post I linked, here is a strace for 6.8.9.7:

 $ strace -c convert /tmp/test.jpg -limit thread 4 -thumbnail 
100x100 -gravity center -background none -extent 100x100 
/tmp/mpdcover.png
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
100.00    0.000033           1        47           read
  0.00    0.000000           0         3           write
  0.00    0.000000           0        84        31 open
  0.00    0.000000           0        54           close
  0.00    0.000000           0        12         3 stat
  0.00    0.000000           0        52           fstat
  0.00    0.000000           0        10           lseek
  0.00    0.000000           0       117           mmap
  0.00    0.000000           0        72           mprotect
  0.00    0.000000           0        25           munmap
  0.00    0.000000           0         9           brk
  0.00    0.000000           0        11           rt_sigaction
  0.00    0.000000           0        19           rt_sigprocmask
  0.00    0.000000           0         4         1 access
  0.00    0.000000           0         1           clone
  0.00    0.000000           0         1           execve
  0.00    0.000000           0         2           getdents
  0.00    0.000000           0         1           getcwd
  0.00    0.000000           0         1           readlink
  0.00    0.000000           0         2           getrlimit
  0.00    0.000000           0        18           times
  0.00    0.000000           0         1           arch_prctl
  0.00    0.000000           0         8           futex
  0.00    0.000000           0         1           sched_getaffinity
  0.00    0.000000           0         1           set_tid_address
  0.00    0.000000           0         2         1 openat
  0.00    0.000000           0         1           set_robust_list
------ ----------- ----------- --------- --------- ----------------
100.00    0.000033                   559        36 total

and for 6.8.9.8
$ strace -c convert /tmp/test.jpg -limit thread 4 -thumbnail 
100x100 -gravity center -background none -extent 100x100 
/tmp/mpdcover.png
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 56.99    0.001325          29        46           munmap
 43.01    0.001000          18        56           futex
  0.00    0.000000           0        50           read
  0.00    0.000000           0         4           write
  0.00    0.000000           0        89        31 open
  0.00    0.000000           0        59           close
  0.00    0.000000           0        23        13 stat
  0.00    0.000000           0        55           fstat
  0.00    0.000000           0        10           lseek
  0.00    0.000000           0       139           mmap
  0.00    0.000000           0        76           mprotect
  0.00    0.000000           0        12           brk
  0.00    0.000000           0        11           rt_sigaction
  0.00    0.000000           0        19           rt_sigprocmask
  0.00    0.000000           0         5         1 access
  0.00    0.000000           0         9           madvise
  0.00    0.000000           0         3           clone
  0.00    0.000000           0         1           execve
  0.00    0.000000           0         2           getdents
  0.00    0.000000           0         1           getcwd
  0.00    0.000000           0         1           readlink
  0.00    0.000000           0         2           getrlimit
  0.00    0.000000           0        56           times
  0.00    0.000000           0         1           arch_prctl
  0.00    0.000000           0         1           sched_getaffinity
  0.00    0.000000           0         1           set_tid_address
  0.00    0.000000           0         2         1 openat
  0.00    0.000000           0         1           set_robust_list
------ ----------- ----------- --------- --------- ----------------
100.00    0.002325                   735        46 total

If you have a specific perf command that would be more revealing?

> Date: Thu, 16 Oct 2014 19:54:21 -0700
> From: anatol.pomozov at gmail.com
> To: arch-general at archlinux.org
> Subject: Re: [arch-general] imagemagick 6.8.9.8-1 is slower than 6.8.9.7-1
> 
> Hi
> 
> On Thu, Oct 16, 2014 at 7:39 PM, Matthew Wynn <m-wynn at live.com> wrote:
> 
> > After upgrading to imagemagick 6.8.9.8-1, I've found it to be a lot slower
> > than 6.8.9.7-1.  I only get this issue when downloading from the
> > repositories or using the PKGBUILD, not when compiling using the
> > instructions at imagemagic.org.
> >
> > I've discussed the issue with the ImageMagick developers, which you can
> > find at
> > http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=26369&sid=a29400f51bd723e98da6b74c0819e9b3.
> > Even when trying to convert a 500x500 image to 100x100, it appears that an
> > image that is 2048x1536 is created.
> >
> > I've tried this on multiple Arch machines with the same result.
> >
> 
> Use code profiler (e.g. 'perf') to record information where the tool spends
> its CPU cycles. Then compare what is the difference and why newer version
> is slower.