I've implemented a working driver on my 460EX. it allocates a couple of buffers of 4MB each. I have a custom memcmp algorithm in asm that is extremely fast in user space, but 1/2 as fast when run on these buffers.
my tests are showing that the algorithm seems to be memory bandwidth bound. my guess is that i am having tlb or cache misses (my algo uses the dbct) that is slowing performance. curiously when in user space, i can affect the performance by small changes in the size of the buffer, i.e. 4MB + 32B is fast, 4MB + 4K is much worse. Can i adjust my driver code that is using kmalloc to make sure that the ppc44x has 4MB tlb entries for these and that they stay put? thanks ayman _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
