[GRASS-dev] [GRASS GIS] #2033: Moving g.pnmcomp to lib/display to improve render performance of wxGUI

[GRASS GIS]

#2033: Moving g.pnmcomp to lib/display to improve render performance of wxGUI
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 Reporter:  huhabla                           |       Owner:  grass-dev@…              
     Type:  enhancement                       |      Status:  new                      
 Priority:  major                             |   Milestone:  7.0.0                    
Component:  wxGUI                             |     Version:  svn-trunk                
 Keywords:  display, Python, multiprocessing  |    Platform:  All                      
      Cpu:  All                               |  
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Comment(by glynn):

 Replying to [comment:4 huhabla]:

 Your tests are comparing raw BMP with PNG (which uses zlib compression).
 If you aren't seeing a significant difference between those two, then the
 I/O overhead is negligible and performance is dictated by rendering speed.

 Regardless of whether I/O uses mmap() or write() and read(), disk transfer
 doesn't get involved unless memory pressure is so high that the data gets
 discarded from the cache before it is read. And if memory pressure is that
 high, disk transfer will get involved anyhow when the "memory" buffers are
 swapped out (and if memory pressure is high and you don't have swap, then
 you'll just get an out-of-memory failure).

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2033#comment:5>
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