sched: Add smt_gain

The idea is that multi-threading a core yields more work
capacity than a single thread, provide a way to express a
static gain for threads.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: Gautham R Shenoy <ego@in.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
LKML-Reference: <20090901083826.073345955@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 651dded25720..9c81c921acb3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -921,6 +921,7 @@ struct sched_domain {
         unsigned int newidle_idx;
         unsigned int wake_idx;
         unsigned int forkexec_idx;
+        unsigned int smt_gain;
         int flags;                      /* See SD_* */
         enum sched_domain_level level;
 
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 7402c1a27c4f..6203ae5067ce 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -99,6 +99,7 @@ int arch_update_cpu_topology(void);
                                 | SD_SHARE_CPUPOWER,    \
         .last_balance           = jiffies,              \
         .balance_interval       = 1,                    \
+        .smt_gain               = 1178, /* 15% */       \
 }
 #endif
 #endif /* CONFIG_SCHED_SMT */