Persistent Cache doesn't work

Post any defects you find in the released or beta versions of the ImageMagick software here. Include the ImageMagick version, OS, and any command-line required to reproduce the problem. Got a patch for a bug? Post it here.
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magick
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Re: Persistent Cache doesn't work

Post by magick »

We are still unable to reproduce the problem. If you write to MIFF rather than MPC does you command work? Try your command and add 'limit map 0' to the command-line. Does the the command now work?
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Re: Persistent Cache doesn't work

Post by tmpfs »

MIFF works. It was also the workaround I used.

I posted the comparison with MIFF https://www.imagemagick.org/discourse-s ... 58#p143838

Doubling limits of memory and map has no effect. Doubling area limit makes it work. As previously noted.
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magick
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Re: Persistent Cache doesn't work

Post by magick »

So the problem is with MPC which points to a problem with memory mapping on your OS. Specifically, we allocate the pixel cache on disk and then memory map it. You can confirm by adding -debug cache to your command-line. When IM tries to map the disk file, it fails and returns an exception. Typically this happens when there is not enough free space on the disk partition. Setting -limit map 0 on your command line should work if the problem is just isolated to memory maps. Do these commands work for you?

Code: Select all

convert -debug cache -limit map 0 -size 4000x4000 xc:white xc:white -adjoin 2pages.mpc; convert -debug cache -limit map 0 2pages.mpc info:
convert -debug cache -size 4000x4000 xc:white xc:white -adjoin 2pages.mpc; convert -debug cache -limit map 0 2pages.mpc info:
convert -debug cache -limit map 0 -size 4000x4000 xc:white xc:white -adjoin 2pages.mpc; convert -debug cache 2pages.mpc info:
Which of these commands succeed? The results will further isolate the memory mapping problem.
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