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

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@gmail.com To: arch-general@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 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.