Okay, I have become a little more advanced lately, and was able to compile the kernel zlib and lzo in userspace (last year I gave up...).
So here is the code (with results, the lib file is the compiled lzo 2.03): http://wiki.laptop.org/images/5/5b/Zlibtest5.tar.gz Since I did not find any assembly compressor support (only decompressor), I do not know what did I talked about last time. It could have been that I have been dreaming about that... The program needs a test.dat file, I have used "cat */*>test.dat" in "/var/lib" which gave me a 22 MB file (the code handles a max of 40 MB). The results are consistent with Erik's results. Since ZLIB has a compression level parameter, and LZO has different compressor types, I will test those as well. Now I think that jffs2 (or any other flash filesystem) should use LZO to store the data, so if the limit is the flash write speed then it could write twice as fast. Later, when there is ample power in the battery and no cpu utilization, it should recompress the data either using a better LZO or by ZLIB (of course only those files which are old enough, so it would not recompress files which will be modified soon). And the results: started with block size == 4096 LZO test in size: 22987994 22987994 -> 11575529 (50.354672%) 1.960000 seconds -> 11.185234 MB/sec 11575529 -> 22987994 0.750000 seconds -> 29.230745 MB/sec compared 22987994 bytes OK LZO asm test in size: 22987994 22987994 -> 11575529 (50.354672%) 1.930000 seconds -> 11.359098 MB/sec 11575529 -> 22987994 0.490000 seconds -> 44.740936 MB/sec compared 22987994 bytes OK ZLIB test in size: 22987994 22987994 -> 8982973 (39.076802%) 9.810000 seconds -> 2.234767 MB/sec 8982973 -> 22987994 2.750000 seconds -> 7.972022 MB/sec compared 22987994 bytes OK Greg Smith wrote: > Hi Erik, > > Can you design a test case or two to test the performance of these > compression schemes? > > Thanks, > > Greg S > > _______________________________________________ > Devel mailing list > [email protected] > http://lists.laptop.org/listinfo/devel > > > _______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
