Re: [Yaffs] multithreading question

On Tuesday 02 February 2010 00:29:17 Johan Kotlinski wrote:
> Hi!
> It appears that Yaffs2 multithreading protection is on a very high level
> (mutex wrapping entire fread/fwrite calls).

Are you talking about yaffs direct or the Linux yaffs?
The linux yaffs will be locked on a page-by-page basis and I am going to
change the way yaffs direct does the reading/writing too to only lock on a
page-by-page basis.

The underlying NAND is locked on a apge by page basis too (that's a limitation
of the hardware), so is this really a big concern?


>
> My worry is that if a low-priority task does a large fwrite call, it could
> block high-priority tasks for a long time. Is this an acknowledged problem?

It depends on the OS. Some, without priority inhere, won't have this problem.
> Are there comparable file systems that handle multithreading in a more
> granular way?