Hi Robert, sounds odd indeed. Can you provide the output of dfbdump -a -p ? This should output the pool allocation status, as well as out of which pool your surfaces are coming. Unfortunately, this is only interesting while your test app is running, which means to either build DirectFB with --enable-multi and using fusion.ko, or calling dfbdump statically from your app.
Alternatively, you can do debug=Core/SurfacePool (and maybe debug=Core/SurfPoolLock) if you have debug enabled, this will also output this info more or less. Greets Niels Robert Hildinger wrote: > I'm seeing a curious issue where surface memory seems to be slower than > freshly malloc'ed memory. The platform I am working on is based on an > ARM1176 CPU (without L2 cache) and no graphics acceleration - everything is > software based. I am currently testing DirectFB 1.1.1. > > I created a simple straight blitter with no blending (i.e. A memcpy blitter) > to see if I could increase blitting performance using some special ARM > instructions. What I found when doing this was that if I created two > surfaces with preallocated memory, and then ran my blitter to copy between > the two surfaces, the performance was roughly 38 megapixels/sec, roughly 4 > times lower than the available memory bandwidth. If I ran the exact same > code without first creating a surface out of the preallocated buffers, the > performance jumped to around 128 megapixels/sec - much closer to the memory > bandwith max. > > My question is, what is DirectFB doing to the preallocated memory buffers > that is causing them memcpy's between them to slow down so drastically? Are > the buffers being mmap'ed internally? Is there any way to improve this > situation? > > Thanks! > -Robert Hildinger > > _______________________________________________ > directfb-dev mailing list > directfb-dev@directfb.org > http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-dev > > -- .------------------------------------------. | DirectFB - Hardware accelerated graphics | | http://www.directfb.org/ | "------------------------------------------" _______________________________________________ directfb-dev mailing list directfb-dev@directfb.org http://mail.directfb.org/cgi-bin/mailman/listinfo/directfb-dev
