Re: [Xen-devel] [PATCH v3 19/20] xen/privcmd: Add support for Linux 64KB page granularity

[David Vrabel <david.vrabel@xxxxxxxxxx>]

On 10/08/15 13:03, Stefano Stabellini wrote:
> On Fri, 7 Aug 2015, Julien Grall wrote:
>> -    rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
>> -    return rc < 0 ? rc : err;
>> +    for (i = 0; i < nr_gfn; i++) {
>> +            if ((i % XEN_PFN_PER_PAGE) == 0) {
>> +                    page = pages[i / XEN_PFN_PER_PAGE];
> 
> If this function is going to be called very frequently you might want to
> consider using a shift instead.
> 
>     page = pages[i >> 4];
> 
> With an appropriate macro of course.

This change isn't necessary.  Compilers already turn divides into
suitable shifts.

David

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