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CPU Usage (again)

Posted: 2013-05-24T06:23:31-07:00
by Prosperent
We recently upgraded our cluster to centos 6, and seem to be having cpu usage problems with imagemagick once again. I have edited the policy.xml and changed threads to 1. I verified with convert -list resource that "Thread" is showing 1, yet each convert process is taking up to 900% of our cpu, or 9 of our 12 cpu cores. Even tried export MAGICK_THREAD_LIMIT=1, no change. Any other suggestions?

Re: CPU Usage (again)

Posted: 2013-05-24T06:34:19-07:00
by magick
Curious. We cannot reproduce the problem:
  • -> time convert logo.png -negate null:
    3.981u 0.700s 0:04.12 599.0% 0+0k 0+0io 0pf+0w
    ->export MAGICK_THREAD_LIMIT=1
    -> time convert logo.png -negate null:
    7.078u 0.633s 0:9.03 97.6% 0+0k 0+0io 0pf+0w
A sure way to ensure only 1 thread is to build ImageMagick from source and disable OpenMP with the -disable-openmp configure script command line.

Re: CPU Usage (again)

Posted: 2013-05-24T08:30:26-07:00
by Prosperent
Thank you for the fast reply. I'll give that a try ad report back. I'm just using the default yum binaries currently.