Re: [tip: x86/mm] x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()

[David Hildenbrand <david@redhat.com>]

> +void untrack_pfn_copy(struct vm_area_struct *dst_vma,
> +		struct vm_area_struct *src_vma)
> +{
> +	resource_size_t paddr;
> +	unsigned long size;
> +
> +	if (!(dst_vma->vm_flags & VM_PAT))
> +		return;
> +
> +	/*
> +	 * As the page tables might not have been copied yet, the PAT
> +	 * information is obtained from the src VMA, just like during
> +	 * track_pfn_copy().
> +	 */
> +	if (get_pat_info(src_vma, &paddr, NULL)) {
> +		size = src_vma->vm_end - src_vma->vm_start;
> +		free_pfn_range(paddr, size);
>   	}
>   

@Ingo, can you drop this patch for now? It's supposed to be 
"!get_pat_info" here, and I want to re-verify now that a couple of 
months passed, whether it's all working as expected with that.

(we could actually complain if get_pat_info() would fail at this point, 
let me think about that)

I'll resend once I get to it. Thanks!

-- 
Cheers,

David / dhildenb