Re: Re: [PATCH v2 1/4] virtio_balloon: separate vm events into a function

[zhenwei pi]

On 4/22/24 15:47, David Hildenbrand wrote:
> On 22.04.24 09:42, zhenwei pi wrote:
> > All the VM events related statistics have dependence on
> > 'CONFIG_VM_EVENT_COUNTERS', once any stack variable is required by any
> > VM events in future, we would have codes like:
> >   #ifdef CONFIG_VM_EVENT_COUNTERS
> >        unsigned long foo;
> >   #endif
> >        ...
> >   #ifdef CONFIG_VM_EVENT_COUNTERS
> >        foo = events[XXX] + events[YYY];
> >        update_stat(vb, idx++, VIRTIO_BALLOON_S_XXX, foo);
> >   #endif
> >
> > Separate vm events into a single function, also remove
>
> Why not simply use __maybe_unused for that variable?

1>
static unsigned int update_balloon_stats()
{
    unsigned __maybe_unused long foo;

    ...
#ifdef CONFIG_VM_EVENT_COUNTERS
    foo = events[XXX] + events[YYY];
    update_stat(vb, idx++, VIRTIO_BALLOON_S_XXX, foo);
#endif
}

2>
static inline unsigned int update_balloon_vm_stats()
{
#ifdef CONFIG_VM_EVENT_COUNTERS
    unsigned long foo;

    foo = events[XXX] + events[YYY];
    update_stat(vb, idx++, VIRTIO_BALLOON_S_XXX, foo);
#endif
}

From the point of my view, I don't need to compile code in my brain 
when reading codes for case 2. :)

--
zhenwei pi