Re: [patch] pagecache-2.3.9-H3, bmap & ext2fs cleanup patch

Linus Torvalds (torvalds@transmeta.com)
Sun, 27 Jun 1999 09:54:09 -0700 (PDT)

On Sun, 27 Jun 1999, Ingo Molnar wrote:
>
> > > this will obviously fail if holes are a little bit different and are not
> > > uptodate anymore.
> >
> > "obviously fail" HOW?
>
> i'll have to change the above to do something like:
>
> was_hole = 0;
> if (!buffer_mapped(bh)) {
> if (buffer_uptodate(bh) && !buffer_dirty(bh))
> was_hole = 1;

Why?

Holes aren't special. They shouldn't be. Why do you CARE whether it was a
hole or not?

You should not. I really don't see your point at all. Your changes make
the path more complex for absolutely no gain that I can tell.

> eventually holes are _not_ kept uptodate anymore. They are not kept
> uptodate in this case because i'm trying to do an optimization of 'late
> clearing' of holes, ie. 'late uptodate' (in fact never) holes.)

I think your whole optimization is a pessimization, and makes the normal
case go slower with no win that I can see.

Linus

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