[PATCH] sched: balance timers

Do CPU load averaging over a number of different intervals.  Allow each
interval to be chosen by sending a parameter to source_load and target_load.
0 is instantaneous, idx > 0 returns a decaying average with the most recent
sample weighted at 2^(idx-1).  To a maximum of 3 (could be easily increased).

So generally a higher number will result in more conservative balancing.

Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 21 insertions, 1 deletions

diff --git a/include/asm-i386/topology.h b/include/asm-i386/topology.h
index 6d0f67507b21..0055fbfeec7b 100644
--- a/include/asm-i386/topology.h
+++ b/include/asm-i386/topology.h
@@ -74,6 +74,10 @@ static inline int node_to_first_cpu(int node)
         .imbalance_pct          = 125,                  \
         .cache_hot_time         = (10*1000000),         \
         .cache_nice_tries       = 1,                    \
+        .busy_idx               = 3,                    \
+        .idle_idx               = 1,                    \
+        .newidle_idx            = 2,                    \
+        .wake_idx               = 1,                    \
         .per_cpu_gain           = 100,                  \
         .flags                  = SD_LOAD_BALANCE       \
                                 | SD_BALANCE_EXEC       \
diff --git a/include/asm-x86_64/topology.h b/include/asm-x86_64/topology.h
index 8f77e9f6bc23..fe8d80a15751 100644
--- a/include/asm-x86_64/topology.h
+++ b/include/asm-x86_64/topology.h
@@ -39,7 +39,11 @@ extern int __node_distance(int, int);
         .busy_factor            = 32,                   \
         .imbalance_pct          = 125,                  \
         .cache_hot_time         = (10*1000000),         \
-        .cache_nice_tries       = 1,                    \
+        .cache_nice_tries       = 2,                    \
+        .busy_idx               = 3,                    \
+        .idle_idx               = 2,                    \
+        .newidle_idx            = 1,                    \
+        .wake_idx               = 1,                    \
         .per_cpu_gain           = 100,                  \
         .flags                  = SD_LOAD_BALANCE       \
                                 | SD_BALANCE_NEWIDLE    \
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2c69682b0444..664981ac1fb6 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -488,6 +488,10 @@ struct sched_domain {
         unsigned long long cache_hot_time; /* Task considered cache hot (ns) */
         unsigned int cache_nice_tries;  /* Leave cache hot tasks for # tries */
         unsigned int per_cpu_gain;      /* CPU % gained by adding domain cpus */
+        unsigned int busy_idx;
+        unsigned int idle_idx;
+        unsigned int newidle_idx;
+        unsigned int wake_idx;
         int flags;                      /* See SD_* */
 
         /* Runtime fields. */
diff --git a/include/linux/topology.h b/include/linux/topology.h
index d70e8972c67f..ae9c2216dfa6 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -89,6 +89,10 @@
         .cache_hot_time         = 0,                    \
         .cache_nice_tries       = 0,                    \
         .per_cpu_gain           = 25,                   \
+        .busy_idx               = 0,                    \
+        .idle_idx               = 0,                    \
+        .newidle_idx            = 0,                    \
+        .wake_idx               = 0,                    \
         .flags                  = SD_LOAD_BALANCE       \
                                 | SD_BALANCE_NEWIDLE    \
                                 | SD_BALANCE_EXEC       \
@@ -115,6 +119,10 @@
         .cache_hot_time         = (5*1000000/2),        \
         .cache_nice_tries       = 1,                    \
         .per_cpu_gain           = 100,                  \
+        .busy_idx               = 2,                    \
+        .idle_idx               = 0,                    \
+        .newidle_idx            = 1,                    \
+        .wake_idx               = 1,                    \
         .flags                  = SD_LOAD_BALANCE       \
                                 | SD_BALANCE_NEWIDLE    \
                                 | SD_BALANCE_EXEC       \