Re: [PATCH bpf-next] bpf: add lookup_and_delete_elem support to hashtab

[Denis Salopek <denis.salopek@sartura.hr>]

On Mon, Feb 08, 2021 at 09:44:59PM -0800, Andrii Nakryiko wrote:
> On Wed, Jan 27, 2021 at 9:15 AM Denis Salopek <denis.salopek@sartura.hr> wrote:
> >
> > Extend the existing bpf_map_lookup_and_delete_elem() functionality to
> > hashtab maps, in addition to stacks and queues.
> > Create a new hashtab bpf_map_ops function that does lookup and deletion
> > of the element under the same bucket lock and add the created map_ops to
> > bpf.h.
> > Add the appropriate test case to 'maps' selftests.
> >
> > Signed-off-by: Denis Salopek <denis.salopek@sartura.hr>
> > Cc: Juraj Vijtiuk <juraj.vijtiuk@sartura.hr>
> > Cc: Luka Oreskovic <luka.oreskovic@sartura.hr>
> > Cc: Luka Perkov <luka.perkov@sartura.hr>
> > ---
> 
> I think this patch somehow got lost, even though it seems like a good
> addition. I'd recommend rebasing and re-submitting to let people take
> a fresh look at this.
> 
> It would also be nice to have a test_progs test added, not just
> test_maps. I'd also look at supporting lookup_and_delete for other
> kinds of hash maps (LRU, per-CPU), so that the support is more
> complete. Thanks!
> 

Hi Andrii,

I'll also implement the LRU and per-CPU ones and resubmit. I don't quite
understand the test_progs, what kind of test(s) exactly should I add there?

Denis

> >  include/linux/bpf.h                     |  1 +
> >  kernel/bpf/hashtab.c                    | 38 +++++++++++++++++++++++++
> >  kernel/bpf/syscall.c                    |  9 ++++++
> >  tools/testing/selftests/bpf/test_maps.c |  7 +++++
> >  4 files changed, 55 insertions(+)
> >
> 
> [...]