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

From: Wu, Feng
Date: Mon Jan 25 2016 - 20:10:26 EST




> -----Original Message-----
> From: Paolo Bonzini [mailto:pbonzini@xxxxxxxxxx]
> Sent: Tuesday, January 26, 2016 12:15 AM
> To: Radim KrcmÃr <rkrcmar@xxxxxxxxxx>
> Cc: Wu, Feng <feng.wu@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> kvm@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v3 2/4] KVM: x86: Use vector-hashing to deliver lowest-
> priority interrupts
>
>
>
> On 25/01/2016 16:20, Radim KrcmÃr wrote:
> > 2016-01-25 13:25+0100, Paolo Bonzini:
> >> On 22/01/2016 15:01, Radim KrcmÃr wrote:
> >>>> for (i = 0; i <= mod; i++) {
> >>>> idx = find_next_bit(bitmap, bitmap_size, idx + 1);
> >>>> BUG_ON(idx == bitmap_size);
> >>>> }
> >>
> >> WARN_ON, not BUG_ON.
> >
> > Callers don't check the return value for an error, because every error
> > is a BUG now. I think that we should check if we return bitmap_size.
> > (Current paths could dereference NULL or throw unrelated warnings.)
>
> You can probably just return a random number (e.g. zero or
> find_first_bit) if the bug is hit. But really, the bug is easy enough
> to verify that BUG_ON might even be okay...

Thanks a lot for your comments, Radim and Paolo! Any other comments
to other patches in this series. If this is the only comments, do I need to
send v5?

Thanks,
Feng

>
> Paolo