sched/core: Enable increased load resolution on 64-bit kernels

[linux-2.6-block.git] / kernel / sched / sched.h

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 0b6a838e9e73499566ef20c1a83be8cf7501bb48..066a4c2d2695417e50a2b0b31ef4179bfe8281d8 100644 (file)
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -49,11 +49,13 @@ static inline void cpu_load_update_active(struct rq *this_rq) { }
  * and does not change the user-interface for setting shares/weights.
  *
  * We increase resolution only if we have enough bits to allow this increased
- * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
- * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
- * increased costs.
+ * resolution (i.e. 64bit). The costs for increasing resolution when 32bit are
+ * pretty high and the returns do not justify the increased costs.
+ *
+ * Really only required when CONFIG_FAIR_GROUP_SCHED is also set, but to
+ * increase coverage and consistency always enable it on 64bit platforms.
  */
-#if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load  */
+#ifdef CONFIG_64BIT
 # define SCHED_LOAD_RESOLUTION 10
 # define scale_load(w)         ((w) << SCHED_LOAD_RESOLUTION)
 # define scale_load_down(w)    ((w) >> SCHED_LOAD_RESOLUTION)