Re: [PATCH v3 2/4] KVM: x86: Use vector-hashing to deliver lowest-priority interrupts

From: Radim KrcmÃr
Date: Fri Jan 22 2016 - 09:02:14 EST


2016-01-22 05:12+0000, Wu, Feng:
>> From: Radim KrÄmÃÅ [mailto:rkrcmar@xxxxxxxxxx]
>> 2016-01-20 09:42+0800, Feng Wu:
>> > +{
>> > + u32 mod;
>> > + int i, idx = 0;
>> > +
>> > + mod = vector % dest_vcpus;
>> > +
>> > + for (i = 0; i <= mod; i++) {
>> > + idx = find_next_bit(bitmap, bitmap_size, idx) + 1;
>>
>> I'd remove this "+ 1". Current users don't check for errors and always
>> do "- 1". The new error value could be 'idx = bitmap_size', with u32 as
>> return type.
>>
>
> Does the following code look good to you:
>
> u32 mod;
> int i, idx = -1;
>
> mod = vector % dest_vcpus;
>
> for (i = 0; i <= mod; i++) {
> idx = find_next_bit(bitmap, bitmap_size, idx + 1);
> BUG_ON(idx == bitmap_size);
> }
>
> return idx;

It's ok, thanks.