Re: [Qemu-devel] [PATCH, RESEND] kvm: Fix dirty tracking with large kernel page size

[Jan Kiszka]

On 2012-04-04 16:24, David Gibson wrote:
> On Wed, Apr 04, 2012 at 12:58:37PM +0200, Jan Kiszka wrote:
>> On 2012-04-04 03:12, David Gibson wrote:
>>>> Also, what's about coalesced MMIO? I see that the ring definition
>>>> depends on [TARGET_]PAGE_SIZE. What page size does the power kernel use
>>>> for it, and does it make a relevant difference for space?
>>>
>>> Hr, so the HV variant of Power KVM doesn't do coalesced mmio.  The PR
>>> variant does, but I don't know enough about it to easily answer that.
>>> If there's a bug there, it hasn't bitten yet, so how about we fix that
>>> another day.
>>
>> Not really a smart approach, specifically now that we are aware of a
>> potential problem here.
> 
> My point is that the fact that there may be another bug out there
> should sure as hell not hold up putting this bug fix in.  The bugs may
> have similar causes and solutions, but they're entirely different code
> paths and the other fix will in no way replace or subsume this one.

I don't disagree. Maybe I over-interpreted your reply as "let's wait if
this actually bites us".

Jan

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