Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220927132753.750069-1-kuba@kernel.org> <CANn89iL4m=aMjZ1XWFNWDyyyDBF1uhNocN0OFqhm2VMm_JQOog@mail.gmail.com>
 <20220927111758.1d25ea0f@kernel.org>
In-Reply-To: <20220927111758.1d25ea0f@kernel.org>
From:   Eric Dumazet <edumazet@google.com>
Date:   Tue, 27 Sep 2022 11:38:36 -0700
Message-ID: <CANn89iKujNcWC7jLRN_6cTCwadyt7Hid6i39i3g3gKwBUvGovg@mail.gmail.com>
Subject: Re: [PATCH net-next] net: drop the weight argument from netif_napi_add
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     David Miller <davem@davemloft.net>,
        netdev <netdev@vger.kernel.org>, Paolo Abeni <pabeni@redhat.com>,
        kvalo@kernel.org, Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless <linux-wireless@vger.kernel.org>,
        Marc Kleine-Budde <mkl@pengutronix.de>,
        linux-can@vger.kernel.org, Jiri Pirko <jiri@resnulli.us>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, Sep 27, 2022 at 11:18 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Tue, 27 Sep 2022 10:54:49 -0700 Eric Dumazet wrote:
> > On Tue, Sep 27, 2022 at 6:28 AM Jakub Kicinski <kuba@kernel.org> wrote:
> > > We tell driver developers to always pass NAPI_POLL_WEIGHT
> > > as the weight to netif_napi_add(). This may be confusing
> > > to newcomers, drop the weight argument, those who really
> > > need to tweak the weight can use netif_napi_add_weight().
> > >
> > > Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> >
> > Sure, but this kind of patch makes backports harder.
> > Not sure how confused are newcomers about this NAPI_POLL_WEIGHT....
>
> I maintained this patch in my tree for a couple of releases (because
> I was waiting for the _weight() version to propagate to non-netdev
> trees) and the conflicts were minor. Three or so cases of new features
> added to drivers which touched the NAPI calls (WiFi and embedded) and
> the strlcpy -> strscpy patch, and, well, why did we take that in if we
> worry about backports...
>
> NAPI weight was already dead when I started hacking on the kernel
> 10 years ago. I don't think it's reasonable to keep dead stuff
> in our APIs for backport's sake. Adding Jiri to CC in case I need
> someone to back me up :)
>
> The idea for this patch came because I was reviewing a driver which
> was trying to do something clever with the weight.
>

No hard feelings, but the recent removal of netif_tx_napi_add() added
extra work for some of us ;)

Keeping around few helpers to keep API a bit stable would help I think.