Re: [Qemu-devel] [PATCH 2/3] memory-device: break the loop if no hint is provided

[Wei Yang <richardw.yang@linux.intel.com>]

On Mon, Jul 29, 2019 at 09:45:24AM +0200, David Hildenbrand wrote:
>On 28.07.19 15:13, Wei Yang wrote:
>> When there is no hint, the first un-overlapped range is the proper one.
>> Just break the loop instead of iterate the whole list.
>> 
>> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
>> ---
>>  hw/mem/memory-device.c | 2 ++
>>  1 file changed, 2 insertions(+)
>> 
>> diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
>> index df3261b32a..413b514586 100644
>> --- a/hw/mem/memory-device.c
>> +++ b/hw/mem/memory-device.c
>> @@ -180,6 +180,8 @@ static uint64_t memory_device_get_free_addr(MachineState *ms,
>>                  range_make_empty(&new);
>>                  break;
>>              }
>> +        } else if (!hint) {
>> +            break;
>>          }
>>      }
>>  
>> 
>
>I think
>
>a) This is fine. I was not able to construct a counter-example where
>this would not work. Whenever we modify the range, we check against the
>next one in the sorted list. If there is no overlap, it fits. And, it
>won't overlap with any other range (and therefore never be changed again)
>
>b) This should therefore not change the assignment order / break migration.
>
>Maybe mention that this will not change the assigned addresses compared
>to old code in all scenarios.
>

Thanks, let me add this in change log.

>Reviewed-by: David Hildenbrand <david@redhat.com>
>
>-- 
>
>Thanks,
>
>David / dhildenb

-- 
Wei Yang
Help you, Help me