From: Nick Piggin <nickpiggin@yahoo.com.au>
Date: Sat, 25 Jun 2005 21:57:17 +0000 (-0700)
Subject: [PATCH] sched: no aggressive idle balancing
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=cafb20c1f9976a70d633bb1e1c8c24eab00e4e80;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git

[PATCH] sched: no aggressive idle balancing

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>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/include/asm-i386/topology.h b/include/asm-i386/topology.h
index 0055fbfeec7b..5eb6f61dcefc 100644
--- a/include/asm-i386/topology.h
+++ b/include/asm-i386/topology.h
@@ -82,7 +82,6 @@ static inline int node_to_first_cpu(int node)
 	.flags			= SD_LOAD_BALANCE	\
 				| SD_BALANCE_EXEC	\
 				| SD_BALANCE_NEWIDLE	\
-				| SD_WAKE_IDLE		\
 				| SD_WAKE_BALANCE,	\
 	.last_balance		= jiffies,		\
 	.balance_interval	= 1,			\
diff --git a/include/asm-x86_64/topology.h b/include/asm-x86_64/topology.h
index fe8d80a15751..9cb7459ce722 100644
--- a/include/asm-x86_64/topology.h
+++ b/include/asm-x86_64/topology.h
@@ -48,7 +48,6 @@ extern int __node_distance(int, int);
 	.flags			= SD_LOAD_BALANCE	\
 				| SD_BALANCE_NEWIDLE	\
 				| SD_BALANCE_EXEC	\
-				| SD_WAKE_IDLE		\
 				| SD_WAKE_BALANCE,	\
 	.last_balance		= jiffies,		\
 	.balance_interval	= 1,			\
diff --git a/include/linux/topology.h b/include/linux/topology.h
index ae9c2216dfa6..b23ec64df7f1 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -127,7 +127,6 @@
 				| SD_BALANCE_NEWIDLE	\
 				| SD_BALANCE_EXEC	\
 				| SD_WAKE_AFFINE	\
-				| SD_WAKE_IDLE		\
 				| SD_WAKE_BALANCE,	\
 	.last_balance		= jiffies,		\
 	.balance_interval	= 1,			\
diff --git a/kernel/sched.c b/kernel/sched.c
index 5ae3568eed0b..396724a2519f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -414,22 +414,6 @@ static inline 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
@@ -1652,12 +1636,11 @@ int can_migrate_task(task_t *p, runqueue_t *rq, int this_cpu,
 
 	/*
 	 * 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))