[PATCH] sched: use softirq for load balancing

Call rebalance_tick (renamed to run_rebalance_domains) from a newly introduced
softirq.

We calculate the earliest time for each layer of sched domains to be rescanned
(this is the rescan time for idle) and use the earliest of those to schedule
the softirq via a new field "next_balance" added to struct rq.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Peter Williams <pwil3058@bigpond.net.au>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index de7593f4e895..e36e86c869fb 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -231,7 +231,8 @@ enum
         NET_TX_SOFTIRQ,
         NET_RX_SOFTIRQ,
         BLOCK_SOFTIRQ,
-        TASKLET_SOFTIRQ
+        TASKLET_SOFTIRQ,
+        SCHED_SOFTIRQ,
 };
 
 /* softirq mask and active fields moved to irq_cpustat_t in