Re: MM patches against 2.5.31

Andrew Morton
2002-08-28T21:01:22Z

Daniel Phillips wrote:
>
> Going right back to basics, what do you suppose is wrong with the 2.4
> strategy of always doing the lru removal in free_pages_ok?

That's equivalent to what we have at present, which is:

if (put_page_testzero(page)) {
/* window here */
lru_cache_del(page);
__free_pages_ok(page, 0);
}

versus:

spin_lock(lru lock);
page = list_entry(lru, ...);
if (page_count(page) == 0)
continue;
/* window here */
page_cache_get(page);
page_cache_release(page); /* double-free */