Re: page_launder() bug

From: Marcelo Tosatti (marcelo@conectiva.com.br)
Date: Mon May 07 2001 - 17:26:55 EST


On Mon, 7 May 2001, Linus Torvalds wrote:

>
> On Mon, 7 May 2001, Marcelo Tosatti wrote:
> >
> > So the "dead_swap_page" logic is _not_ buggy and you are full of shit when
> > telling Alan to revert the change. (sorry, I could not avoid this one)
>
> Well, the problem is that the patch _is_ buggy.
>
> swap_writepage() does it right. And dead_swap_page does it wrong. It
> doesn't look at the swap counts, for one thing.

So lets fix it and make it look for the swap counts.

> The patch should be reverted. The fact that other parts of the system do
> it _right_ is not an argument for mm/vmscan.c to do it wrong.

My point is that its _ok_ for us to check if the page is a dead swap cache
page _without_ the lock since writepage() will recheck again with the page
_locked_. Quoting you two messages back:

"But it is important to re-calculate the deadness after getting the lock.
Before, it was just an informed guess. After the lock, it is knowledge."

See ?

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Mon May 07 2001 - 21:00:26 EST