Re: [PATCH net-next v2 01/18] jump_label: export static_key_slow_{inc,dec}_cpuslocked()

Maciej Fijalkowski
2024-10-22T12:52:49Z

On Mon, Oct 21, 2024 at 03:53:40PM +0200, Alexander Lobakin wrote:
> From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
> Date: Thu, 17 Oct 2024 13:06:25 +0200
>
> > On Tue, Oct 15, 2024 at 04:53:33PM +0200, Alexander Lobakin wrote:
> >> Sometimes, there's a need to modify a lot of static keys or modify the
> >> same key multiple times in a loop. In that case, it seems more optimal
> >> to lock cpu_read_lock once and then call _cpuslocked() variants.
> >> The enable/disable functions are already exported, the refcounted
> >> counterparts however are not. Fix that to allow modules to save some
> >> cycles.
> >
> > Hi Olek,
> >
> > can you explain how is this at all related to the patchset that it
> > contains? AFAIK I don't see it being used in later changes?
>
> See libeth/xdp.c in patch #18, it's used to enable XDPSQ sharing static key.

I got tricked by define in include/linux/jump_label.h and I was directly
grepping for funcs being exported:)

Not sure who should ack it though.

>
> >
> >>
> >> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
> >> ---
> >> kernel/jump_label.c | 2 ++
> >> 1 file changed, 2 insertions(+)
> >>
> >> diff --git a/kernel/jump_label.c b/kernel/jump_label.c
> >> index 93a822d3c468..1034c0348995 100644
> >> --- a/kernel/jump_label.c
> >> +++ b/kernel/jump_label.c
> >> @@ -182,6 +182,7 @@ bool static_key_slow_inc_cpuslocked(struct static_key *key)
> >> }
> >> return true;
> >> }
> >> +EXPORT_SYMBOL_GPL(static_key_slow_inc_cpuslocked);
> >>
> >> bool static_key_slow_inc(struct static_key *key)
> >> {
> >> @@ -342,6 +343,7 @@ void static_key_slow_dec_cpuslocked(struct static_key *key)
> >> STATIC_KEY_CHECK_USE(key);
> >> __static_key_slow_dec_cpuslocked(key);
> >> }
> >> +EXPORT_SYMBOL_GPL(static_key_slow_dec_cpuslocked);
> >>
> >> void __static_key_slow_dec_deferred(struct static_key *key,
> >> struct delayed_work *work,
> >> --
> >> 2.46.2
> >>
>
> Thanks,
> Olek