Re: do we want to kill VM_RESERVED or not? [was Re: 2.6.5-rc1-aa3]

[Marc-Christian Petersen <m.c.p@wolk-project.de>]

On Monday 22 March 2004 13:42, Andrea Arcangeli wrote:

Hi Andrea,

> I see, the below patch will avoid your oops (I also removed the stack
> trace dump from memory.c since it's useless to get the stack trace from
> there and this will reduce the noise).
> --- x/mm/memory.c.~1~	2004-03-21 15:21:42.000000000 +0100
> +++ x/mm/memory.c	2004-03-22 13:40:26.852849384 +0100
> @@ -324,9 +324,11 @@ skip_copy_pte_range:
>  					 * Device driver pages must not be
>  					 * tracked by the VM for unmapping.
>  					 */
> -					BUG_ON(!page_mapped(page));
> -					BUG_ON(!page->mapping);
> -					page_add_rmap(page, vma, address, PageAnon(page));
> +					if (likely(page_mapped(page) && page->mapping))
> +						page_add_rmap(page, vma, address, PageAnon(page));
> +					else
> +						printk("Badness in %s at %s:%d\n",
> +						       __FUNCTION__, __FILE__, __LINE__);
>  				} else {
>  					BUG_ON(page_mapped(page));
>  					BUG_ON(page->mapping);
> @@ -1429,7 +1431,9 @@ retry:
>  	 * real anonymous pages, they're "device" reserved pages instead.
>  	 */
>  	reserved = !!(vma->vm_flags & VM_RESERVED);
> -	WARN_ON(reserved == pageable);
> +	if (unlikely(reserved == pageable))
> +		printk("Badness in %s at %s:%d\n",
> +		       __FUNCTION__, __FILE__, __LINE__);
>
>  	/*
>  	 * Should we do an early C-O-W break?

Perfect. Thanks alot.


> many thanks for the help!

You're welcome. Thanks for your help!

ciao, Marc