Re: [PATCHv1] x86/xen: add reschedule point when mapping foreign GFNs

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

On 10/27/2015 07:50 AM, David Vrabel wrote:
> Mapping a large range of foreign GFNs can take a long time, add a
> reschedule point after each batch of 16 GFNs.
>
> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
> ---
>   arch/x86/xen/mmu.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
> index 9c479fe..734fa84 100644
> --- a/arch/x86/xen/mmu.c
> +++ b/arch/x86/xen/mmu.c
> @@ -2882,6 +2882,7 @@ static int do_remap_gfn(struct vm_area_struct *vma,
>   				mapped += done;
>   			batch_left -= done;
>   			index += done;
> +			cond_resched();
>   		} while (batch_left);
>   
>   		nr -= batch;

Shouldn't this be done in the outer (i.e. 'while (nr)') loop? The inner 
loop always processes 16 pages.

-boris