Re: Ext2fs patch

[Marco Gerards]

"Yoshinori K. Okuji" <address@hidden> writes:

[...]

> > I wonder if it is wise to read blocks before the block you want to
> > read.  I think this usually doesn't make much sense.  Usually
> > filesystems are optimized to read forwards.
> 
> That's right. The current implementation is just for simplicity (in other 
> words, because I was lazy), so it is not perfect from performance point of 
> view.
> 
> However, I suspect that there would be no gain from making the cache system 
> work better by always reading blocks forwards. Normally, reading some blocks 
> at a time is quite fast (i.e. it does not differ from reading a single block 
> very much). And, even if it reads some unnecessary blocks, when you read a 
> file sequentially, the overhead would be negligible. As PUPA reads at most 8 
> blocks at a time, if you read more than 800 blocks sequentially, the overhead 
> is less 1%.

I agree with you.  What I meant with that filesystems are optimized to
read forwards is that they read data sequentially.  What about adding
a todo item to improve caching?

> > The new patch is included in this mail.  I've also updated the
> > copyright years, I forgot some in my previous patch *blush*.
> 
> Now is the time to commit. :)

Done! :)

Thanks,
Marco