On Wed, 10 Aug 2005, Dave Hansen wrote: > On Wed, 2005-08-10 at 18:27 +0100, Mel Gorman wrote: > > I later linearly scan the mem_map looking for pages that can be freed up > > (usually LRU pages). I was expecting any page with PG_inode set to have a > > page->mapping but not all of them do. It is the pages without a ->mapping > > that are confusing the hell out of me. > > How about putting a check for PG_inode and a periodic dump_stack() > wherever page->mapping is cleared? That should at least let you catch > the culprit who is clearing them. __remove_from_page_cache() is the only > real place I see this being done. >
Will do, it might shed some light on whats happening. > Are you remembering to clean PG_inode when a page is freed? Yes, I was using the allocator to count how many inode-related pages there were in the system. The answer was lots, another reason why I'm thinking that I picked the worst possible benchmark to test this stuff with. > Perhaps > it's allocated for the page cache, reclaimed, returned to the allocator, > and reallocated as anonymous memory where you're seeing the null > ->mapping. Might want to check for PG_inode in free_pages_check(). > I am 99.99% certain I make that check but I can't double check the code until late in the weekend. -- Mel Gorman Part-time Phd Student Java Applications Developer University of Limerick IBM Dublin Software Lab - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
