On Fri, Sep 22, 2023 at 1:13 PM Christian Marangi <ansuelsmth@xxxxxxxxx> wrote:
>
> We currently have napi_if_scheduled_mark_missed that can be used to
> check if napi is scheduled but that does more thing than simply checking
> it and return a bool. Some driver already implement custom function to
> check if napi is scheduled.
>
> Drop these custom function and introduce napi_is_scheduled that simply
> check if napi is scheduled atomically.
>
> Update any driver and code that implement a similar check and instead
> use this new helper.
>
> Signed-off-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
> ---
> drivers/net/ethernet/chelsio/cxgb3/sge.c | 8 --------
> drivers/net/wireless/realtek/rtw89/core.c | 2 +-
> include/linux/netdevice.h | 5 +++++
> net/core/dev.c | 2 +-
> 4 files changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/ethernet/chelsio/cxgb3/sge.c b/drivers/net/ethernet/chelsio/cxgb3/sge.c
> index 2e9a74fe0970..71fa2dc19034 100644
> --- a/drivers/net/ethernet/chelsio/cxgb3/sge.c
> +++ b/drivers/net/ethernet/chelsio/cxgb3/sge.c
> @@ -2501,14 +2501,6 @@ static int napi_rx_handler(struct napi_struct *napi, int budget)
> return work_done;
> }
>
> -/*
> - * Returns true if the device is already scheduled for polling.
> - */
> -static inline int napi_is_scheduled(struct napi_struct *napi)
> -{
> - return test_bit(NAPI_STATE_SCHED, &napi->state);
> -}
> -
> /**
> * process_pure_responses - process pure responses from a response queue
> * @adap: the adapter
> diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c
> index 133bf289bacb..bbf4ea3639d4 100644
> --- a/drivers/net/wireless/realtek/rtw89/core.c
> +++ b/drivers/net/wireless/realtek/rtw89/core.c
> @@ -1744,7 +1744,7 @@ static void rtw89_core_rx_to_mac80211(struct rtw89_dev *rtwdev,
> struct napi_struct *napi = &rtwdev->napi;
>
> /* In low power mode, napi isn't scheduled. Receive it to netif. */
> - if (unlikely(!test_bit(NAPI_STATE_SCHED, &napi->state)))
> + if (unlikely(!napi_is_scheduled(napi)))
> napi = NULL;
>
> rtw89_core_hw_to_sband_rate(rx_status);
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index db3d8429d50d..8eac00cd3b92 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -482,6 +482,11 @@ static inline bool napi_prefer_busy_poll(struct napi_struct *n)
> return test_bit(NAPI_STATE_PREFER_BUSY_POLL, &n->state);
> }
>
In which context is it safe to call this helper ?
I fear that making this available will add more bugs.
For instance rspq_check_napi() seems buggy to me.
> +static inline bool napi_is_scheduled(struct napi_struct *n)
const ...
> +{
> + return test_bit(NAPI_STATE_SCHED, &n->state);
> +}
> +
> bool napi_schedule_prep(struct napi_struct *n);
>
> /**
> diff --git a/net/core/dev.c b/net/core/dev.c
> index cc03a5758d2d..32ba8002f65a 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -6523,7 +6523,7 @@ static int __napi_poll(struct napi_struct *n, bool *repoll)
> * accidentally calling ->poll() when NAPI is not scheduled.
> */
> work = 0;
> - if (test_bit(NAPI_STATE_SCHED, &n->state)) {
> + if (napi_is_scheduled(n)) {
> work = n->poll(n, weight);
> trace_napi_poll(n, work, weight);
> }
> --
> 2.40.1
>
