Alexei Starovoitov wrote:
> On Mon, Feb 26, 2024 at 3:21 PM John Fastabend <john.fastabend@xxxxxxxxx> wrote:
> > > +__bpf_kfunc int *bpf_iter_bits_next(struct bpf_iter_bits *it)
> > > +{
> > > + struct bpf_iter_bits_kern *kit = (void *)it;
> > > + const unsigned long *bits = kit->bits;
> > > + int bit;
> > > +
> > > + if (!bits)
> > > + return NULL;
> > > +
> > > + bit = find_next_bit(bits, kit->nr_bits, kit->bit + 1);
> >
> > Seems like this should be ok over unsafe memory as long as find_next_bit
> > is bounded?
>
> Are you proposing to add find_next_bit() as a kfunc instead?
I was suggesting you could likely implement find_next_bit() in
BPF directly no need for a kfunc.
>
> With the bpf_can_loop() proposal these two can be combined and
> it will probably achieve the same result.
> But imo this iterator is small enough to get in now and
> delete later when there is a better way.
Agree its fine to go in as is IMO. Mostly just curious if anyone
tried to implement it in BPF.
> Ideally we'd need to add new instructions to operate with bits efficiently.
+1.
