[PATCH] sched: add option to serialize load balancing

Large sched domains can be very expensive to scan.  Add an option SD_SERIALIZE
to the sched domain flags.  If that flag is set then we make sure that no
other such domain is being balanced.

[akpm@osdl.org: build fix]
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/topology.h b/include/linux/topology.h
index b93bb6cc6cc2..6c5a6e6e813b 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -194,7 +194,8 @@
         .wake_idx               = 0, /* unused */       \
         .forkexec_idx           = 0, /* unused */       \
         .per_cpu_gain           = 100,                  \
-        .flags                  = SD_LOAD_BALANCE,      \
+        .flags                  = SD_LOAD_BALANCE       \
+                                | SD_SERIALIZE, \
         .last_balance           = jiffies,              \
         .balance_interval       = 64,                   \
         .nr_balance_failed      = 0,                    \