From: Nick Piggin <nickpiggin@yahoo.com.au>
Remove the very aggressive idle stuff that has recently gone into 2.6 - it is
going against the direction we are trying to go. Hopefully we can regain
performance through other methods.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/include/asm-i386/topology.h | 1 -
25-akpm/include/asm-x86_64/topology.h | 1 -
25-akpm/include/linux/topology.h | 1 -
25-akpm/kernel/sched.c | 25 ++++---------------------
4 files changed, 4 insertions(+), 24 deletions(-)
diff -puN include/asm-i386/topology.h~sched-remove-aggressive-idle-balancing include/asm-i386/topology.h
--- 25/include/asm-i386/topology.h~sched-remove-aggressive-idle-balancing 2005-02-24 19:54:53.000000000 -0800
+++ 25-akpm/include/asm-i386/topology.h 2005-02-24 19:54:53.000000000 -0800
@@ -85,7 +85,6 @@ static inline cpumask_t pcibus_to_cpumas
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_EXEC \
| SD_BALANCE_NEWIDLE \
- | SD_WAKE_IDLE \
| SD_WAKE_BALANCE, \
.last_balance = jiffies, \
.balance_interval = 1, \
diff -puN include/asm-x86_64/topology.h~sched-remove-aggressive-idle-balancing include/asm-x86_64/topology.h
--- 25/include/asm-x86_64/topology.h~sched-remove-aggressive-idle-balancing 2005-02-24 19:54:53.000000000 -0800
+++ 25-akpm/include/asm-x86_64/topology.h 2005-02-24 19:54:53.000000000 -0800
@@ -58,7 +58,6 @@ static inline cpumask_t __pcibus_to_cpum
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_NEWIDLE \
| SD_BALANCE_EXEC \
- | SD_WAKE_IDLE \
| SD_WAKE_BALANCE, \
.last_balance = jiffies, \
.balance_interval = 1, \
diff -puN include/linux/topology.h~sched-remove-aggressive-idle-balancing include/linux/topology.h
--- 25/include/linux/topology.h~sched-remove-aggressive-idle-balancing 2005-02-24 19:54:53.000000000 -0800
+++ 25-akpm/include/linux/topology.h 2005-02-24 19:54:53.000000000 -0800
@@ -124,7 +124,6 @@
| SD_BALANCE_NEWIDLE \
| SD_BALANCE_EXEC \
| SD_WAKE_AFFINE \
- | SD_WAKE_IDLE \
| SD_WAKE_BALANCE, \
.last_balance = jiffies, \
.balance_interval = 1, \
diff -puN kernel/sched.c~sched-remove-aggressive-idle-balancing kernel/sched.c
--- 25/kernel/sched.c~sched-remove-aggressive-idle-balancing 2005-02-24 19:54:53.000000000 -0800
+++ 25-akpm/kernel/sched.c 2005-02-24 19:54:53.000000000 -0800
@@ -414,22 +414,6 @@ static runqueue_t *this_rq_lock(void)
return rq;
}
-#ifdef CONFIG_SCHED_SMT
-static int cpu_and_siblings_are_idle(int cpu)
-{
- int sib;
- for_each_cpu_mask(sib, cpu_sibling_map[cpu]) {
- if (idle_cpu(sib))
- continue;
- return 0;
- }
-
- return 1;
-}
-#else
-#define cpu_and_siblings_are_idle(A) idle_cpu(A)
-#endif
-
#ifdef CONFIG_SCHEDSTATS
/*
* Called when a process is dequeued from the active array and given
@@ -1652,16 +1636,15 @@ int can_migrate_task(task_t *p, runqueue
/*
* Aggressive migration if:
- * 1) the [whole] cpu is idle, or
+ * 1) task is cache cold, or
* 2) too many balance attempts have failed.
*/
- if (cpu_and_siblings_are_idle(this_cpu) || \
- sd->nr_balance_failed > sd->cache_nice_tries)
+ if (sd->nr_balance_failed > sd->cache_nice_tries)
return 1;
if (task_hot(p, rq->timestamp_last_tick, sd))
- return 0;
+ return 0;
return 1;
}
@@ -2133,7 +2116,7 @@ static void active_load_balance(runqueue
if (cpu_isset(cpu, visited_cpus))
continue;
cpu_set(cpu, visited_cpus);
- if (!cpu_and_siblings_are_idle(cpu) || cpu == busiest_cpu)
+ if (cpu == busiest_cpu)
continue;
target_rq = cpu_rq(cpu);
_