Re: [patch 1/6] mempolicy: convert MPOL constants to enum

[Paul Jackson <pj@sgi.com>]

David wrote:

+enum {
+	MPOL_DEFAULT,
+	MPOL_PREFERRED,
+	MPOL_BIND,
+	MPOL_INTERLEAVE,
+	MPOL_MAX,	/* always last member of enum */

Aren't the values that these constants take part of the
user visible kernel API?

In other words, if someone added another MPOL_* in the middle
of this enum, it would break mbind/set_mempolicy/get_mempolicy
users, right:

+enum {
+	MPOL_DEFAULT,
+	MPOL_PREFERRED,
+	MPOL_YET_ANOTHER_FLAG,		/* <== added flag ... oops */
+	MPOL_BIND,
+	MPOL_INTERLEAVE,
+	MPOL_MAX,	/* always last member of enum */

I'm thinking that we should still specify the specific value
of each of these flags, by way of documenting these necessary
values, as in:

+enum {
+	MPOL_DEFAULT = 0,
+	MPOL_PREFERRED = 1,
+	MPOL_BIND = 2,
+	MPOL_INTERLEAVE = 3,
+	MPOL_MAX,	/* always last member of enum */


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