Re: [Qemu-devel] [RFC v4 1/9] exec.c: Add new exclusive bitmap to ram_list

[alvise rigo]

On Tue, Aug 11, 2015 at 5:55 PM, Paolo Bonzini <address@hidden> wrote:
>
>
> On 11/08/2015 17:54, alvise rigo wrote:
>> This can lead to an excessive rate of flush requests, since for one
>> CPU that removes the TLB_EXCL flag, all the others that are competing
>> for the same excl address will need to flush the entire cache and
>> start all over again.
>
> Why flush the entire cache (I understand you mean TLB)?

Sorry, I meant the TLB.
If for each removal of an exclusive entry we set also the bit to 1, we
force the following LL to make a tlb_flush() on every vCPU.

alvise

>
> Paolo
>
>> If for a start we want to have a simpler implementation, I can revert
>> back to the one-bit design.