Re: [PATCH v2 bpf-next] bpf: use raw_spin_trylock() for pcpu_freelist_push/pop in NMI

[Daniel Borkmann <daniel@xxxxxxxxxxxxx>]

On 10/5/20 8:03 PM, Martin KaFai Lau wrote:
> On Mon, Oct 05, 2020 at 09:58:38AM -0700, Song Liu wrote:
[...]
> > non-NMI pop(): 	use _lock(); check per cpu lists first;
> >                  if all per cpu lists are empty, check extralist;
> >                  if extralist is empty, return NULL.
> >
> > non-NMI push(): use _lock(); only push to per cpu lists.
> >
> > NMI pop():    use _trylock(); check per cpu lists first;
> >                if all per cpu lists are locked or empty, check extralist;
> >                if extralist is locked or empty, return NULL.
> >
> > NMI push():   use _trylock(); check per cpu lists first;
> >                if all per cpu lists are locked; try push to extralist;
> >                if extralist is also locked, keep trying on per cpu lists.
> >
> > Reported-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> > Signed-off-by: Song Liu <songliubraving@xxxxxx>
> >
> > ---
> > Changes v1 => v2:
> > 1. Update commit log. (Daniel)
> Acked-by: Martin KaFai Lau <kafai@xxxxxx>

LGTM, applied, thanks!