On Tue, May 28, 2024 at 09:12:02AM +0000, Pankaj Raghav (Samsung) wrote:
> On Tue, May 28, 2024 at 09:00:00AM +1000, Dave Chinner wrote:
> > On Mon, May 27, 2024 at 11:43:43PM +0100, Matthew Wilcox wrote:
> > > On Mon, May 27, 2024 at 11:39:47PM +0100, Matthew Wilcox wrote:
> > > > > > + AS_FOLIO_ORDER_MIN = 16,
> > > > > > + AS_FOLIO_ORDER_MAX = 21, /* Bits 16-25 are used for FOLIO_ORDER */
> > > > > > };
> > > > > >
> > > > > > +#define AS_FOLIO_ORDER_MIN_MASK 0x001f0000
> > > > > > +#define AS_FOLIO_ORDER_MAX_MASK 0x03e00000
> > > > >
> > > > > As you changed the mapping flag offset, these masks also needs to be
> > > > > changed accordingly.
> > > >
> > > > That's why I did change them?
> > >
> > > How about:
> > >
> > > -#define AS_FOLIO_ORDER_MIN_MASK 0x001f0000
> > > -#define AS_FOLIO_ORDER_MAX_MASK 0x03e00000
> > > +#define AS_FOLIO_ORDER_MIN_MASK (31 << AS_FOLIO_ORDER_MIN)
> > > +#define AS_FOLIO_ORDER_MAX_MASK (31 << AS_FOLIO_ORDER_MAX)
> >
> > Lots of magic numbers based on the order having only having 5 bits
> > of resolution. Removing that magic looks like this:
> >
> > AS_FOLIO_ORDER_BITS = 5,
>
> I think this needs to be defined outside of the enum as 5 is already
> taken by AS_NO_WRITEBACK_TAGS? But I like the idea of making it generic
> like this.
Duplicate values in assigned enums are legal and fairly common.
This:
enum {
FOO = 1,
BAR = 2,
BAZ = 1,
};
int main(int argc, char *argv[])
{
printf("foo %d, bar %d, baz %d\n", FOO, BAR, BAZ);
}
compiles without warnings or errors and gives the output:
foo 1, bar 2, baz 1
-Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
