Re: [Yaffs] YAFFS vs JFFS2

As Thomas says, the compression in JFFS2 will help in some cases
(particularly if you have highly compressable test files).

There are many factors to consider as part of performance measurement
including:
1) Comparison of writes and reads of the files you're likely to use - not
just test files.
2) Comparison of performance on a dirty file system (ie. how do they compare
with garbage collection etc.)
3) Testing overwrite (ie. overwriting parts of a file).

The reason both YAFFS and JFFS2 exist is that they both have different
properties. One is not always better than the other. To get the best
performance you need to select the right file system based on your needs.

-- CHarles


On Wednesday 24 November 2004 04:45, Thomas Gleixner wrote:
> On Tue, 2004-11-23 at 15:25 +0100, Lorenzo PARISI wrote:
> > Hi,
> >
> > I've done this writing on NAND:
> > 1) 4000 files whit size 4k
> > 2) 250 files, 64k
> > 3) 32 files, 1M
> > 4) 4 files, 8M
> > 5) 2 files, 16M
> > 6) 1 file with size 1M.
> >

> > And, the results are:
> >       JFFS2        YAFFS
> >       -----        -----
> > 1)    1m50         2m1
> > 2)    0m15         0m42
> > 3)    0m17         1m18
> > 4)    0m17         1m21
> > 5)    0m17         1m24
> > 6)    0m25         1m28

> >
> > The results are much differents. Why?
>
> JFFS2 is compressing the files and writes less bytes to the chip.
> Depending on the file content the compression can be fast and reduce the
> size quite well. So it's hard to compare.
>
> tglx
>
>
>
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