[Pkg-gmagick-im-team] Bug#941724: imagemagick: underuses available resources (memory, disk space)

[Matt Roberds]

Package: imagemagick-6-common
Version: 8:6.9.7.4+dfsg-11+deb9u10
Followup-For: Bug #941724

Hello all!

I agree with this suggestion.  I was trying to figure out why
ImageMagick performed slowly on my machine, and I came across this bug.

To give some numbers, the desktop machine I'm writing this on is about
10 years old, with a 2.9 GHz dual-core processor, 4 GB RAM, and 1 TB
rotating hard drive.  On this system:


ImageMagick 6 with the default policy.xml:

---
$ time convert -size 5100x6600 xc:red red.pnm

real    0m1.952s
user    0m0.192s
sys     0m0.628s

$ time convert red.pnm red.png

real    0m11.310s
user    0m1.136s
sys     0m0.768s
---

The total wall-clock time is 13.262 sec.


ImageMagick 6 with *no* policy.xml at all:

---
$ time convert -size 5100x6600 xc:red red.pnm

real    0m0.670s
user    0m0.168s
sys     0m0.480s

$ time convert red.pnm red.png

real    0m1.318s
user    0m1.036s
sys     0m0.380s
---

The total wall-clock time is 1.988 sec, for about a 6.7x (!!!)
improvement.

The other details on this desktop system from reportbug are below.

I also tried the same tests on a laptop I have that runs Debian 10, with
a 2.16 GHz dual-core CPU, 4 GB RAM, and a 500 GB rotating hard drive.

On that machine, with the default policy.xml, the two operations above
took 9.340 sec of wall-clock time.  With *no* policy.xml, the same
operations took 5.750 sec, or about a 1.6x improvement.

Also, bug 860763 is probably related to this one:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=860763

Thanks!

Matt Roberds


-- Package-specific info:
ImageMagick program version
---------------------------
animate:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
compare:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
convert:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
composite:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
conjure:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
display:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
identify:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
import:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
mogrify:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
montage:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
stream:  ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org

-- System Information:
Debian Release: 9.13
   APT prefers oldstable-updates
   APT policy: (500, 'oldstable-updates'), (500, 'oldstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-13-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages imagemagick depends on:
ii  imagemagick-6.q16  8:6.9.7.4+dfsg-11+deb9u10

imagemagick recommends no packages.

imagemagick suggests no packages.

-- no debconf information