JFFS3 & performance

Joakim Tjernlund joakim.tjernlund at lumentis.se
Wed Dec 22 10:30:20 EST 2004


> Here is backward engel32.  It runs about 1.5% faster than forward
> engel32 in my hash test.  Other backward algorithms should be in the
> same order (depending on hardware).

Hi again

Can you do
1) First run a forward and then a backward version on memory space >= 2*L1 cache
2) Then do two forward runs on the same memory.

Compare the delta between 1) and 2)
That should give a clue if it is worth having a backward version.

> 
> Adler32 beats the hell out of every other algorithm.  Except for the
> backwards part, it appears to be a clear winner.

Have you look at the assembler Engler32 generates? Every instruction counts
in such small loops.

 Jocke

PS.
 I am levaing for Christmas in 2 hours and will be offline more or less until January
 so I guess I won't be much help in the near future.





More information about the linux-mtd mailing list