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

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Date:	Tue, 26 Jan 2016 01:10:17 +0000
From:	"Wu, Feng" <feng.wu@...el.com>
To:	Paolo Bonzini <pbonzini@...hat.com>,
	Radim Krcmár <rkrcmar@...hat.com>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"Wu, Feng" <feng.wu@...el.com>
Subject: RE: [PATCH v3 2/4] KVM: x86: Use vector-hashing to deliver
 lowest-priority interrupts



> -----Original Message-----
> From: Paolo Bonzini [mailto:pbonzini@...hat.com]
> Sent: Tuesday, January 26, 2016 12:15 AM
> To: Radim Krcmár <rkrcmar@...hat.com>
> Cc: Wu, Feng <feng.wu@...el.com>; linux-kernel@...r.kernel.org;
> kvm@...r.kernel.org
> Subject: Re: [PATCH v3 2/4] KVM: x86: Use vector-hashing to deliver lowest-
> priority interrupts
> 
> 
> 
> On 25/01/2016 16:20, Radim Krcmár wrote:
> > 2016-01-25 13:25+0100, Paolo Bonzini:
> >> On 22/01/2016 15:01, Radim Krcmár 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