Re: [PATCH] net/core: Export dev_core_stats_rx_dropped_inc sets

[Yajun Deng]

On 2023/9/13 02:05, Eric Dumazet wrote:
> On Tue, Sep 12, 2023 at 8:03 PM Eric Dumazet <edumazet@xxxxxxxxxx> wrote:
>
> > Sure, this was what was suggested (perhaps not _very_ precisely, but
> > the general idea was pretty clear).
> > v2 seems ok, right ?
> >
> > It seems we are all on the same page.
> >
> > +static __cold struct net_device_core_stats __percpu
> > *dev_core_stats(struct net_device *dev)
> > +{
> > +       /* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
> > +       struct net_device_core_stats __percpu *p = READ_ONCE(dev->core_stats);
> > +
> > +       if (likely(p))
> > +               return p;
> > +
> > +       return netdev_core_stats_alloc(dev);
> > +}
> > +
> > +#define DEV_CORE_STATS_INC(FIELD)                              \
> > +void dev_core_stats_##FIELD##_inc(struct net_device *dev)      \
> > +{                                                              \
> > +       struct net_device_core_stats __percpu *p;               \
> > +                                                               \
> > +       p = dev_core_stats(dev);                                \
> > +       if (p)                                                  \
> > +               this_cpu_inc(p->FIELD);                         \
> > +}                                                              \
> > +EXPORT_SYMBOL(dev_core_stats_##FIELD##_inc)
> Oh well, I just read the patch, and it seems wrong indeed.
>
> netdev_core_stats_alloc() is the one that can be cold.

Okay, I would add __cold to netdev_core_stats_alloc() in v3.

Olek suggest that define a new dev_core_stats_inc() function.

I hope to see the suggestion in another reply.