[PATCH] sched domain: increase the SMT busy rebalance interval

With SMT, if the logical processor is busy, load balance happens for every
8msec(min)-16msec(max).  There is no need to do this often, as this is just
for fairness(to maintain uniform runqueue lengths) and default time slice
anyhow is 100msec.

Appended patch increases this interval to 64msec(min)-128msec(max) when the
logical processor is busy.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/include/linux/topology.h b/include/linux/topology.h
index da508d1998e413714ee788a4602d2a6478dba96d..b93bb6cc6cc2826f97f2a9cca3205a00923f1471 100644 (file)
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -93,7 +93,7 @@
        .groups                 = NULL,                 \
        .min_interval           = 1,                    \
        .max_interval           = 2,                    \
-       .busy_factor            = 8,                    \
+       .busy_factor            = 64,                   \
        .imbalance_pct          = 110,                  \
        .cache_nice_tries       = 0,                    \
        .per_cpu_gain           = 25,                   \