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

[Andrea Arcangeli <andrea@suse.de>]

On Sun, Mar 21, 2004 at 01:00:05PM +0100, Andrea Arcangeli wrote:
> On Sun, Mar 21, 2004 at 12:49:39PM +0100, Andrea Arcangeli wrote:
> > the additional hardness you could remove the BUG_ON on in memory.c at line
> 
> I now discovered that WARN_ON exists too, so probably the best is to
> simply change that to a WARN_ON (or to a printk). If one will ever do a
> pagetable walk again, one has to change that to a BUG_ON by that time.
> Kernel will work stable regardless of that condition triggering.
> 
> --- x/mm/memory.c.~1~	2004-03-20 22:12:43.000000000 +0100
> +++ x/mm/memory.c	2004-03-21 12:59:05.331923016 +0100
> @@ -1429,7 +1429,7 @@ retry:
>  	 * real anonymous pages, they're "device" reserved pages instead.
>  	 */
>  	reserved = !!(vma->vm_flags & VM_RESERVED);
> -	BUG_ON(reserved == pageable);
> +	WARN_ON(reserved == pageable);
>  
>  	/*
>  	 * Should we do an early C-O-W break?

and here the vmware proper fix:

--- vmmon-only/linux/driver.c.~1~	2004-03-21 13:07:02.869326296 +0100
+++ vmmon-only/linux/driver.c	2004-03-21 13:07:28.320457136 +0100
@@ -1083,6 +1083,7 @@ static int LinuxDriverMmap(struct file *
    }
    /* Clear VM_IO, otherwise SuSE's kernels refuse to do get_user_pages */
    vma->vm_flags &= ~VM_IO;
+   vma->vm_flags |= VM_RESERVED;
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 2, 3)
    vma->vm_file = filp;
    filp->f_count++;


You should apply both (though just applying one of the two will fix it).