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

Alexander Lobakin
2024-10-21T13:54:23Z

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.

>
>>
>> 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