Re: innd mmap bug in 2.4.0-test12

Daniel Phillips
2000-12-24T20:40:15Z

Linus Torvalds wrote:
> Hmm.. I wonder if such a dirty page might have been moved to the
> "inactive_clean" list some way? It shouldn't really be there, as the page
> had users, but if it gets on that list we'd not have tested the dirty bit.
>
> Marco, would you mind changing the test in reclaim_page(), somewheer
> around line mm/vmscan.c:487 that says:
>
> /* The page is dirty, or locked, move to inactive_dirty list. */
> if (page->buffers || TryLockPage(page)) {
> ...
>
> and change the test to
>
> if (page->buffers || PageDirty(page) || TryLockPage(page)) {
>
> instead? Ie ad the test for "PageDirty(page)"

Good point. Up until recently the page dirty bit wasn't actually being
set anywhere and page->buffers was acting as kind of a surrogate dirty
bit - page_launder would call try_to_free_buffers which would find the
dirty buffers and fail out, but start io first

It looks like PG_dirty is now being used only for swap_cache pages, and
not for buffer cache and page cache pages, is that correct?

--
Daniel