[Yaffs] YAFFS vs JFFS2

[Charles Manning]

As Thomas says, the compression in JFFS2 will help in some cases=20
(particularly if you have highly compressable test files).

There are many factors to consider as part of performance measurement=20
including:
1) Comparison of writes and reads of the files you're likely to use - not=
=20
just test files.
2) Comparison of performance on a dirty file system (ie. how do they comp=
are=20
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=20
properties. One is not always better than the other.  To get the best=20
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 th=
e
> size quite well. So it's hard to compare.
>
> tglx
>
>
>
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