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From: Gautham R Shenoy <ego@in.ibm.com>
To: "Ingo Molnar" <mingo@elte.hu>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org,
	Suresh Siddha <suresh.b.siddha@intel.com>,
	"Balbir Singh" <balbir@in.ibm.com>,
	Gautham R Shenoy <ego@in.ibm.com>
Subject: [PATCH v4 3/5] sched: Rename the variable sched_mc_preferred_wakeup_cpu
Date: Tue, 31 Mar 2009 16:20:27 +0530	[thread overview]
Message-ID: <20090331105027.16414.21798.stgit@sofia.in.ibm.com> (raw)
In-Reply-To: <20090331104829.16414.11385.stgit@sofia.in.ibm.com>

sched_mc_preferred_wakeup_cpu is currently used when the user seeks
power savings through aggressive task consolidation.

But this functionality is applicable for both sched_mc_power_savings as
well as sched_smt_power_savings. So rename
sched_mc_preferred_wakeup_cpu to preferred_wakeup_cpu.

Also fix the comment for preferred_wakeup_cpu.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
---

 kernel/sched.c      |   12 +++++++-----
 kernel/sched_fair.c |    2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 07b774e..36d116b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -542,11 +542,13 @@ struct root_domain {
 #endif
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
 	/*
-	 * Preferred wake up cpu nominated by sched_mc balance that will be
-	 * used when most cpus are idle in the system indicating overall very
-	 * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2)
+	 * Preferred wake up cpu which is nominated by load balancer,
+	 * is the CPU on which the tasks would be woken up, which
+	 * otherwise would have woken up on an idle CPU even on a system
+	 * with low-cpu-utilization.
+	 * This is triggered at POWERSAVINGS_BALANCE_WAKEUP(2).
 	 */
-	unsigned int sched_mc_preferred_wakeup_cpu;
+	unsigned int preferred_wakeup_cpu;
 #endif
 };
 
@@ -3451,7 +3453,7 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
 	sds->busiest = sds->group_min;
 
 	if (active_power_savings_level >= POWERSAVINGS_BALANCE_WAKEUP) {
-		cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu =
+		cpu_rq(this_cpu)->rd->preferred_wakeup_cpu =
 			group_first_cpu(sds->group_leader);
 	}
 
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 02324d2..dacb0d8 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1052,7 +1052,7 @@ static int wake_idle(int cpu, struct task_struct *p)
 
 	this_cpu = smp_processor_id();
 	chosen_wakeup_cpu =
-		cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu;
+		cpu_rq(this_cpu)->rd->preferred_wakeup_cpu;
 
 	if (active_power_savings_level >= POWERSAVINGS_BALANCE_WAKEUP &&
 		idle_cpu(cpu) && idle_cpu(this_cpu) &&


  parent reply	other threads:[~2009-03-31 10:51 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-31 10:50 [PATCH v4 0/5] sched: Extend sched_mc/smt_power_savings framework Gautham R Shenoy
2009-03-31 10:50 ` [PATCH v4 1/5] sched: code cleanup - sd_power_saving_flags(), sd_balance_for_*_power() Gautham R Shenoy
2009-03-31 10:50 ` [PATCH v4 2/5] sched: Record the current active power savings level Gautham R Shenoy
2009-08-24 16:09   ` Peter Zijlstra
2009-08-25  9:12     ` Gautham R Shenoy
2009-03-31 10:50 ` Gautham R Shenoy [this message]
2009-03-31 10:50 ` [PATCH v4 4/5] sched: Arbitrate the nomination of preferred_wakeup_cpu Gautham R Shenoy
2009-03-31 10:50 ` [PATCH v4 5/5] sched: Fix sd_parent_degenerate for SD_POWERSAVINGS_BALANCE Gautham R Shenoy

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