Re: [Xen-devel] [PATCH 3/6] xen-gntdev: Remove unneeded structures from grant_map tracking data

[Jeremy Fitzhardinge <jeremy@xxxxxxxx>]

On 12/14/2010 01:52 PM, Daniel De Graaf wrote:
> On 12/14/2010 04:15 PM, Jeremy Fitzhardinge wrote:
>> On 12/14/2010 06:55 AM, Daniel De Graaf wrote:
>>> The entire hypercall argument list isn't required; only selected
>>> fields from the hypercall need to be tracked between the ioctl, map,
>>> and unmap operations.
>> Is the rationale of this patch to save memory?  If so, how much does it
>> save.
>>
>> (This patch seems sensible in principle, but it doesn't seem to save
>> much complexity.)
>>
>>     J
> This will also allow easier testing of what pages need to be unmapped
> (more obvious in the HVM version). I also find it less confusing to
> populate the hypercall arguments immediately before the hypercall, but
> that's likely a matter of opinion. It only saves 46 bytes per page, so
> if it seems more complex it could be dropped.

I like it in general.  See the other mail I just sent - you can use the
multicall API to remove all the allocations for the arguments, and that
should help a lot.

    J

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel