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

From: zhenwei pi
Date: Mon Apr 22 2024 - 04:04:20 EST




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