Re: [PATCH for-next] IB/core: Only update PKEY and GID caches on respective events

[Leon Romanovsky <leon@kernel.org>]

On Tue, May 04, 2021 at 01:46:24PM +0200, Håkon Bugge wrote:
> Both the PKEY and GID tables in an HCA can hold in the order of
> hundreds entries. Reading them are expensive. Partly because the API
> for retrieving them only returns a single entry at a time. Further, on
> certain implementations, e.g., CX-3, the VFs are paravirtualized in
> this respect and have to rely on the PF driver to perform the
> read. This again demands VF to PF communication.
> 
> IB Core's cache is refreshed on all events. Hence, filter the refresh
> of the PKEY and GID caches based on the event received being
> IB_EVENT_PKEY_CHANGE and IB_EVENT_GID_CHANGE respectively.
> 
> Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
> ---
>  drivers/infiniband/core/cache.c | 25 ++++++++++++++++---------
>  1 file changed, 16 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c
> index 5c9fac7..531ae6b 100644
> --- a/drivers/infiniband/core/cache.c
> +++ b/drivers/infiniband/core/cache.c
> @@ -1472,10 +1472,14 @@ static int config_non_roce_gid_cache(struct ib_device *device,
>  }
>  
>  static int
> -ib_cache_update(struct ib_device *device, u8 port, bool enforce_security)
> +ib_cache_update(struct ib_device *device, u8 port, enum ib_event_type event,
> +		bool reg_dev, bool enforce_security)
>  {
>  	struct ib_port_attr       *tprops = NULL;
> -	struct ib_pkey_cache      *pkey_cache = NULL, *old_pkey_cache;
> +	struct ib_pkey_cache      *pkey_cache = NULL;
> +	struct ib_pkey_cache      *old_pkey_cache = NULL;
> +	bool			   update_pkey_cache = (reg_dev || event == IB_EVENT_PKEY_CHANGE);
> +	bool			   update_gid_cache = (reg_dev || event == IB_EVENT_GID_CHANGE);

I'm not super excited to see "events" in this function and would be more
happy to see it is handled in ib_cache_event_task() while the function
signature will be:
ib_cache_update(struct ib_device *device, u8 port, bool all_gids, bool
all_pkeys, bool enforce_security)

Thanks