Re: [RFC PATCH 08/11] sched: Remove SD_WAKE_AFFINE flag and replace it with SD_BALANCE_WAKE

[Mike Galbraith]

On Thu, 2016-06-23 at 14:04 +0100, Matt Fleming wrote:

> I'm curious - doesn't this break userspace ABI? These flags are
> exported via procfs, so I would have assumed removing or changing the
> value of any of these constants would be forbidden.

Nope, if those change, you get to fix up your toys.  Hopping in the way
way back machine...

@ -460,10 +460,11 @@ enum idle_type
 #define SD_LOAD_BALANCE		1	/* Do load balancing on this domain. */
 #define SD_BALANCE_NEWIDLE	2	/* Balance when about to become idle */
 #define SD_BALANCE_EXEC		4	/* Balance on exec */
-#define SD_WAKE_IDLE		8	/* Wake to idle CPU on task wakeup */
-#define SD_WAKE_AFFINE		16	/* Wake task to waking CPU */
-#define SD_WAKE_BALANCE		32	/* Perform balancing at task wakeup */
-#define SD_SHARE_CPUPOWER	64	/* Domain members share cpu power */
+#define SD_BALANCE_FORK		8	/* Balance on fork, clone */
+#define SD_WAKE_IDLE		16	/* Wake to idle CPU on task wakeup */
+#define SD_WAKE_AFFINE		32	/* Wake task to waking CPU */
+#define SD_WAKE_BALANCE		64	/* Perform balancing at task wakeup */
+#define SD_SHARE_CPUPOWER	128	/* Domain members share cpu power */