Re: page_launder() bug

[Marcelo Tosatti]

On 7 May 2001, Linus Torvalds wrote:

> 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. And you can use informed guesses for heuristics, but you
> must _not_ use them for any serious decisions.

And thats what swap_writepage() is doing:

static int swap_writepage(struct page *page)
{
        /* One for the page cache, one for this user, one for page->buffers */
        if (page_count(page) > 2 + !!page->buffers)
                goto in_use;
        if (swap_count(page) > 1)
                goto in_use;

...
}