[Yaffs-archive] Re: newbie to yaffs -->locking

Steve

I am about to check in some stuff that fixes some probs. I will email when
I've done the checkin.

Try this, you might find your problems go away.

-- Charles

On Tue, 17 Sep 2002 14:33, Steve Tsai wrote:
> Do you mean that yaffs will lock only delete file and resize file? But I
> use tar to unpack some files to flash and yaffs seems lock the file
> system. I think it just copy files.
>
> Steve Tsai
>
> > -----Original Message-----
> > From: Charles Manning [mailto:manningc2@actrix.gen.nz]
> > Sent: Saturday, September 14, 2002 4:10 AM
> > To: Steve Tsai; 'Charles Manning'
> > Cc: yaffs@toby-churchill.org
> > Subject: Re: newbie to yaffs -->locking
> >
> >
> > Right now yaffs uses gross locking on the file system. Only
> > one thread can be
> > in yaffs at a time. For most cases this is not a significant
> > problem since
> > the underlying NAND is locked per operation anyway.
> >
> > There are two cases where yaffs can lock "for a long time" if
> > the generic
> > read/write interface is used:
> > * Delete file: YAFFS locks while the whole file deletes
> > (approx 0.5 secs for
> > a 1MB file).
> > * Resize a file: Resizing from say 1MB to 0 will take approx 0.5 secs.
> >
> > I have code in development to do background file deletion.
> > This spreads the
> > deletion load over the next n write operations.
> >
> > I am reluctant to add finer grain locking yet since this
> > complicates the
> > code. I don't think the payback is warranted yet (ie. more
> > important things
> > to do).
> >
> > -- CHarles
> >
> > On Fri, 13 Sep 2002 17:22, Steve Tsai wrote:
> > > I rollback yaffs_fs.c to revision 1.12, and it have not the
> >
> > problem 1
> >
> > > and 2. Right now yaffs will lock the fs when program write
> >
> > data to it
> >
> > > and other program will be blocked to read data from yaffs.
> >
> > How can I
> >
> > > improve it?
>
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