Re: [PATCH mptcp-next v19 3/9] mptcp: add sched_data_set_contexts helper

[Geliang Tang <geliang.tang@suse.com>]

On Fri, Nov 18, 2022 at 10:26:01AM -0800, Mat Martineau wrote:
> On Fri, 18 Nov 2022, Matthieu Baerts wrote:
> 
> > Hi Geliang, Mat,
> > 
> > On 11/11/2022 08:47, Geliang Tang wrote:
> > > Add a new helper mptcp_sched_data_set_contexts() to set the subflow
> > > pointers array in struct mptcp_sched_data. It will be invoked by the
> > > BPF schedulers to export the subflow pointers to the BPF contexts.
> > 
> > I have an issue with the CI and this commit: it adds a new helper which
> > is not used before before "selftests/bpf: Add mptcp sched structs" commit.
> > 
> > We then have this warning when compiling with W=1:
> > 
> >  $ make W=1 net/mptcp/sched.o
> >  net/mptcp/sched.c:97:6: warning: symbol
> > 'mptcp_sched_data_set_contexts' was not declared. Should it be static?
> > 
> > I'm not sure what to do:
> > - modify the script to parse error and ignore it (I would prefer to
> > avoid case per case)
> > - move the commit after "selftests/bpf: Add mptcp sched structs" and
> > directly use it (extern + kfunc)
> > - squash it elsewhere?
> > - add a patch like that:
> > 
> > ------------------- 8< -------------------
> > diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
> > index 0d7c73e9562e..e9b1ff932a3b 100644
> > --- a/net/mptcp/sched.c
> > +++ b/net/mptcp/sched.c
> > @@ -94,6 +94,8 @@ void mptcp_subflow_set_scheduled(struct
> > mptcp_subflow_context *subflow,
> >        WRITE_ONCE(subflow->scheduled, scheduled);
> > }
> > 
> > +#pragma GCC diagnostic push
> > +#pragma GCC diagnostic ignored "-Wmissing-prototypes"
> > void mptcp_sched_data_set_contexts(const struct mptcp_sock *msk,
> >                                   struct mptcp_sched_data *data)
> > {
> > @@ -112,3 +114,4 @@ void mptcp_sched_data_set_contexts(const struct
> > mptcp_sock *msk,
> >        for (; i < MPTCP_SUBFLOWS_MAX; i++)
> >                data->contexts[i] = NULL;
> > }
> > +#pragma GCC diagnostic pop
> > ------------------- 8< -------------------
> 
> One more option:
> 
> Add a declaration in net/mptcp/protocol.h
> 
> 
> > 
> > But well... :-)
> > 
> > I suggest to apply this patch for the moment to avoid errors with all
> > new patches and check later which solution to use.
> 
> This is fine with me, if you'd rather wait for a squash-to patch.

Hi Mat, Matt,

I just sent a squash-to patch to fix this.

Thanks,
-Geliang


> 
> --
> Mat Martineau
> Intel