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/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
| |
 |