[Qemu-devel] Re: [PATCH] fix endless look at kvm migration

[Jan Kiszka <jan.kiszka@web.de>]

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Alexander Graf wrote:
> 
> On 27.07.2009, at 20:44, Jan Kiszka wrote:
> 
>> Glauber Costa wrote:
>>> If we try to sync bitmaps withouth KVM_MEM_LOG_DIRTY_PAGES being set
>>> on a slot, we will enter an endless loop. Remove the test, since it
>>> is not strictly needed anyway
>>>
>>> Signed-off-by: Glauber Costa <glommer@redhat.com>
>>> CC: Alexander Graf <agraf@suse.de>
>>> ---
>>> kvm-all.c |    5 -----
>>> 1 files changed, 0 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/kvm-all.c b/kvm-all.c
>>> index 824bb4c..d3bbd3c 100644
>>> --- a/kvm-all.c
>>> +++ b/kvm-all.c
>>> @@ -331,11 +331,6 @@ int
>>> kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
>>>             break;
>>>         }
>>>
>>> -        /* We didn't activate dirty logging? Don't care then. */
>>> -        if(!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES)) {
>>> -            continue;
>>> -        }
>>> -
>>>         size = ((mem->memory_size >> TARGET_PAGE_BITS) + 7) / 8;
>>>         if (!d.dirty_bitmap) {
>>>             d.dirty_bitmap = qemu_malloc(size);
>>
>> Please let us revert the whole bd83677.
> 
> Does the non-functional if (r < 0) hurt anyone?

I would reduce the motivation of the next kvm-arch contributor to
implement proper dirty log tracking. :)

> 
> But if you like cleaniness, yes - reverting the whole thing would be
> fine with me too.
> 

There are no users for this in sight, so it's best the clean it up - and
then fix the error check that this discussion has revealed.

Jan


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