On Thu, May 03, 2018 at 01:17:02AM +0300, Kirill A. Shutemov wrote:
> On Wed, May 02, 2018 at 05:26:39PM +0000, Matthew Wilcox wrote:
> > Option 2:
> > + union {
> > + unsigned long counters;
> > + struct {
> > + unsigned inuse:16;
> > + unsigned objects:15;
> > + unsigned frozen:1;
> > + };
> > + };
> >
> > Pro: Expresses exactly what we do.
> > Con: Back to five levels of indentation in struct page
>
> The indentation issue can be fixed (to some extend) by declaring the union
> outside struct page and just use it inside.
>
> I don't advocate for the approach, just listing the option.
Actually, you can't have an anonymous tagged union without -fms-extensions
(which got zero comments when I proposed it to lkml) or -fplan9-extensions
(which would require gcc 4.6)
