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Re: [Xen-devel] Little help with blk ring

On Wed, May 23, 2012 at 5:20 PM, Jan Beulich <JBeulich@xxxxxxxx> wrote:
>>>> On 23.05.12 at 01:43, Daniel Castro <evil.dani@xxxxxxxxx> wrote:
>> On Tue, May 22, 2012 at 8:53 AM, James Harper 
>> <james.harper@xxxxxxxxxxxxxxxx> wrote:
>>> Is sizeof() what you expect it to be? That would cause the first request to
>> be (mostly) okay, but subsequent requests to be further and further out of
>> alignment.
>> Right on the spot!
>> Here is the output of sizeof for the struct and for each member:
>> SIZEOF ring_res:12 id:8 operation:1 status:2
>> There is seems to be an alignment problem, them sum of members is 11,
>> but the whole struct is 12, the question now is, how can I tackle this
>> problem?
> But sizeof is 12, as expected. There should be no place in your
> code where you (directly or indirectly) sum up the individual
> members' sizes.

But if you add the members it is id:8 + operation:1 + status:2 = 11.
Am I missing something?
Jan, the problem is that I am getting id=256 and operation=real_id, so
James suggested to see if there was an alignment problem. In the back
driver there is no place in the code that would assign id=


> Jan

| +---------------------------------+ | This space intentionally blank
for notetaking.
| |   | Daniel Castro,                |
| |   | Consultant/Programmer.|
| |   | U Andes                         |

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