From: Eric Dumazet <edumazet@google.com>
To: Christian Marangi <ansuelsmth@gmail.com>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>,
Raju Rangoju <rajur@chelsio.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Alexandre Torgue <alexandre.torgue@foss.st.com>,
Jose Abreu <joabreu@synopsys.com>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Ping-Ke Shih <pkshih@realtek.com>, Kalle Valo <kvalo@kernel.org>,
Simon Horman <horms@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Jiri Pirko <jiri@resnulli.us>, Hangbin Liu <liuhangbin@gmail.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org,
linux-wireless@vger.kernel.org
Subject: Re: [net-next PATCH 1/3] net: introduce napi_is_scheduled helper
Date: Mon, 2 Oct 2023 14:56:24 +0200 [thread overview]
Message-ID: <CANn89iLKBqsV6=jP1viSNMpA1W8r5mJEitjH3+RU5gEOQFYEtg@mail.gmail.com> (raw)
In-Reply-To: <651abda3.df0a0220.a04f0.12df@mx.google.com>
On Mon, Oct 2, 2023 at 2:55 PM Christian Marangi <ansuelsmth@gmail.com> wrote:
>
> On Mon, Oct 02, 2023 at 02:49:11PM +0200, Eric Dumazet wrote:
> > On Mon, Oct 2, 2023 at 2:43 PM Christian Marangi <ansuelsmth@gmail.com> wrote:
> > >
> > > On Mon, Oct 02, 2023 at 02:35:22PM +0200, Eric Dumazet wrote:
> > > > On Mon, Oct 2, 2023 at 2:29 PM Christian Marangi <ansuelsmth@gmail.com> wrote:
> > > >
> > > > > Ehhh the idea here was to reduce code duplication since the very same
> > > > > test will be done in stmmac. So I guess this code cleanup is a NACK and
> > > > > I have to duplicate the test in the stmmac driver.
> > > >
> > > > I simply wanted to add a comment in front of this function/helper,
> > > > advising not using it unless absolutely needed.
> > > >
> > > > Thus my question "In which context is it safe to call this helper ?"
> > > >
> > > > As long as it was private with a driver, I did not mind.
> > > >
> > > > But if made public in include/linux/netdevice.h, I would rather not
> > > > have to explain
> > > > to future users why it can be problematic.
> > >
> > > Oh ok!
> > >
> > > We have plenty of case similar to this. (example some clock API very
> > > internal that should not be used normally or regmap related)
> > >
> > > I will include some comments warning that this should not be used in
> > > normal circumstances and other warnings. If you have suggestion on what
> > > to add feel free to write them.
> > >
> > > Any clue on how to proceed with the sge driver?
> > >
> >
> > I would remove use of this helper for something with no race ?
> >
> > Feel free to submit this :
> >
> > (Alternative would be to change napi_schedule() to return a boolean)
> >
>
> Think mod napi_schedule() to return a bool would result in massive
> warning (actually error with werror) with return value not handled.
>
It should not, unless we added a __must_check
> I will submit with your Suggested-by. Ok for you?
Absolutely, thanks.
>
> > diff --git a/drivers/net/ethernet/chelsio/cxgb3/sge.c
> > b/drivers/net/ethernet/chelsio/cxgb3/sge.c
> > index 2e9a74fe0970df333226b80af8716f30865c01b7..09d0e6aa4db982e3488e0c28bed33e83453801d0
> > 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
> > @@ -2674,9 +2666,9 @@ static int rspq_check_napi(struct sge_qset *qs)
> > {
> > struct sge_rspq *q = &qs->rspq;
> >
> > - if (!napi_is_scheduled(&qs->napi) &&
> > - is_new_response(&q->desc[q->cidx], q)) {
> > - napi_schedule(&qs->napi);
> > + if (is_new_response(&q->desc[q->cidx], q) &&
> > + napi_schedule_prep(&qs->napi)) {
> > + __napi_schedule(&qs->napi);
> > return 1;
> > }
> > return 0;
>
> --
> Ansuel
next prev parent reply other threads:[~2023-10-02 12:56 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-22 11:12 [net-next PATCH 1/3] net: introduce napi_is_scheduled helper Christian Marangi
2023-09-22 11:12 ` [net-next PATCH 2/3] net: stmmac: improve TX timer arm logic Christian Marangi
2023-09-29 12:38 ` Vincent Whitchurch
2023-09-30 12:04 ` Christian Marangi
2023-09-22 11:12 ` [net-next PATCH 3/3] net: stmmac: increase TX coalesce timer to 5ms Christian Marangi
2023-09-22 12:28 ` Andrew Lunn
2023-09-22 12:39 ` Christian Marangi
2023-09-22 20:02 ` Dave Taht
2023-09-29 21:03 ` [net-next PATCH 1/3] net: introduce napi_is_scheduled helper Nambiar, Amritha
2023-09-30 11:59 ` Eric Dumazet
2023-09-30 12:11 ` Christian Marangi
2023-09-30 13:42 ` Eric Dumazet
2023-10-02 12:29 ` Christian Marangi
2023-10-02 12:35 ` Eric Dumazet
2023-10-02 12:43 ` Christian Marangi
2023-10-02 12:49 ` Eric Dumazet
2023-10-02 12:54 ` Christian Marangi
2023-10-02 12:56 ` Eric Dumazet [this message]
2023-10-02 12:59 ` Eric Dumazet
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