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Commit cafb20c1 authored by Nick Piggin's avatar Nick Piggin Committed by Linus Torvalds
Browse files

[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: default avatarNick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent a3f21bce

include/asm-i386/topology.h

+0 −1
Original line number Diff line number Diff line
@@ -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,			\

include/asm-x86_64/topology.h

+0 −1
Original line number Diff line number Diff line
@@ -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,			\

include/linux/topology.h

+0 −1
Original line number Diff line number Diff line
@@ -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,			\

kernel/sched.c

+2 −19
Original line number Diff line number Diff line
@@ -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))