LZO support

[Erik Garrison]

How are you producing the test data (test.dat) used by the test?

On Sun, Jul 20, 2008 at 10:57:37AM +0200, NoiseEHC wrote:
> 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
>>
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