> On Friday 10 March 2006 16:33, Wolfgang Denk wrote: > > > I believe most of those observations and measurements are not valid > > > anymore. Kernel 2.6 for 8xx has come a long way since this article was > > > written. It might have been true back then, but it surely isn't anymore. > > > > So did you actually run any benchmarks? Specilations on what might be > > or should be are not really helpful. > > Of course I did. Otherwise I wouldn't say this. > > Here's some benchmark data from nbench (sorry didn't try lmbench yet): > > The same ELDK (version 3.1.1) for both kernels, running on exactly the same > board (MPC852T 100MHz, with 32Mbyte SDRAM and 32Mbyte Flash running from NFS > root). I removed some FPU benchmarks, as they are pretty meaningless for this > board and take an ethernity otherwise. > > Results for Kernel 2.4.25 (Denx CVS from around sept-oct or so, 2005): > > TEST : Iterations/sec. : Old Index : New Index > : : Pentium 90* : AMD K6/233* > --------------------:------------------:-------------:------------ > NUMERIC SORT : 30.438 : 0.78 : 0.26 > STRING SORT : 1.5842 : 0.71 : 0.11 > BITFIELD : 7.9506e+06 : 1.36 : 0.28 > FP EMULATION : 3.258 : 1.56 : 0.36 > IDEA : 108.89 : 1.67 : 0.49 > HUFFMAN : 26.281 : 0.73 : 0.23 > LU DECOMPOSITION : 0.32765 : 0.02 : 0.01 > ==========================ORIGINAL BYTEMARK RESULTS========================== > INTEGER INDEX : 1.052 > FLOATING-POINT INDEX: 0.257 > > > Now the results for 2.6.14 (Denx git released 2.6.14): > > TEST : Iterations/sec. : Old Index : New Index > : : Pentium 90* : AMD K6/233* > --------------------:------------------:-------------:------------ > NUMERIC SORT : 32.654 : 0.84 : 0.28 > STRING SORT : 1.7408 : 0.78 : 0.12 > BITFIELD : 8.3466e+06 : 1.43 : 0.30 > FP EMULATION : 3.506 : 1.68 : 0.39 > IDEA : 115.3 : 1.76 : 0.52 > HUFFMAN : 27.855 : 0.77 : 0.25 > LU DECOMPOSITION : 0.35932 : 0.02 : 0.01 > ==========================ORIGINAL BYTEMARK RESULTS========================== > INTEGER INDEX : 1.115 > FLOATING-POINT INDEX: 0.265 > > > I don't know why, but while everyone still says 2.6 is slower, I am > consistently getting results that seem to prove the opposite. Why? > Is the TLB/cache stuff better optimized for 8xx in 2.6? > IMHO it is quite a difference.
Could you please provide more information on the kernel configuration e.g. the .config files and the size of the kernel images? Thanks. Wolfgang. > Btw, I also wrote different small "speed-measurement" tools (to measure > loop-speed, memory throughput for different block sizes, etc...) and they all > show aproximately the same increase. > I was careful to strip both kernels of all unnecessary drivers and features > that could hamper performance. If you wish I could try to dig up the .config > files for you, but I am not sure I'll find them anymore (I did this when > 2.6.14 was just released). > > Greetings, > > -- > David Jander > Protonic Holland. > _______________________________________________ > Linuxppc-embedded mailing list > Linuxppc-embedded at ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-embedded > >
