Re: [PATCHv2, RFC 10/30] thp, mm: locking tail page is a bug

From: Dave Hansen
Date: Thu Mar 21 2013 - 13:18:54 EST


On 03/14/2013 10:50 AM, Kirill A. Shutemov wrote:
> index 0ff3403..38fdc92 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -669,6 +669,7 @@ void __lock_page(struct page *page)
> {
> DEFINE_WAIT_BIT(wait, &page->flags, PG_locked);
>
> + VM_BUG_ON(PageTail(page));
> __wait_on_bit_lock(page_waitqueue(page), &wait, sleep_on_page,
> TASK_UNINTERRUPTIBLE);
> }

Could we get a bit more of a description here in a comment or in the
patch summary about this? It makes some sense to me that code shouldn't
be mucking with the tail pages, but I'm curious what your logic is here,
too. I'm sure you've thought about it a lot more than I have.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/