On 09/24/2012 04:32 PM, Takuya Yoshikawa wrote:
> On Mon, 24 Sep 2012 12:09:00 +0200
> Avi Kivity <avi@xxxxxxxxxx> wrote:
>
>> > while (vcpu->request) {
>> > xchg(vcpu->request, request);
>> >
>> > for_each_set_bit(request) {
>> > clear_bit(X);
>> >
>> > ......
>> > }
>> >
>> > }
>>
>> In fact I had something like that in one of the earlier versions, but it
>> was problematic. I'll try to see what the issue was.
>
> Unless there are many requests, the cost of for_each_set_bit() and a few
> added code may exceed that of the original code.
> (Looping using __ffs() is an alternative because requests is "long".)
>
> So I wanted to know the most common requests pattern.
See other branch of this thread. But in short, I now think you are
right and the special-case is warranted.
(not for STEAL_UPDATE - that's likely a bug, it should only happen on
overcommit)
--
error compiling committee.c: too many arguments to function
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