[git pull] scheduler updates

From: Ingo Molnar
Date: Thu Jan 31 2008 - 16:54:48 EST



Linus, please pull the latest scheduler-fixes git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched.git

Thanks! The only behavioral changes are two fixes for interactivity
problems reported recently. (they may also be backport candidates for
v2.6.24)

Ingo

------------------>
Gerald Stralko (1):
sched: remove unused params

Ingo Molnar (1):
debug: turn ignore_loglevel into an early param

Paul E. McKenney (1):
RCU: add help text for "RCU implementation type"

Peter Zijlstra (1):
sched: let +nice tasks have smaller impact

Srivatsa Vaddagiri (1):
sched: fix high wake up latencies with FAIR_USER_SCHED

init/Kconfig | 8 ++++++++
kernel/printk.c | 4 ++--
kernel/sched.c | 10 +++++-----
kernel/sched_fair.c | 8 ++++++--
4 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index 0d0bbf2..dcc96a8 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -775,6 +775,14 @@ config PREEMPT_NOTIFIERS
choice
prompt "RCU implementation type:"
default CLASSIC_RCU
+ help
+ This allows you to choose either the classic RCU implementation
+ that is designed for best read-side performance on non-realtime
+ systems, or the preemptible RCU implementation for best latency
+ on realtime systems. Note that some kernel preemption modes
+ will restrict your choice.
+
+ Select the default if you are unsure.

config CLASSIC_RCU
bool "Classic RCU"
diff --git a/kernel/printk.c b/kernel/printk.c
index 58bbec6..29ae1e9 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -455,10 +455,10 @@ static int __init ignore_loglevel_setup(char *str)
ignore_loglevel = 1;
printk(KERN_INFO "debug: ignoring loglevel setting.\n");

- return 1;
+ return 0;
}

-__setup("ignore_loglevel", ignore_loglevel_setup);
+early_param("ignore_loglevel", ignore_loglevel_setup);

/*
* Write out chars from start to end - 1 inclusive
diff --git a/kernel/sched.c b/kernel/sched.c
index ba4c880..8355e00 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1255,12 +1255,12 @@ static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);

#define sched_class_highest (&rt_sched_class)

-static void inc_nr_running(struct task_struct *p, struct rq *rq)
+static void inc_nr_running(struct rq *rq)
{
rq->nr_running++;
}

-static void dec_nr_running(struct task_struct *p, struct rq *rq)
+static void dec_nr_running(struct rq *rq)
{
rq->nr_running--;
}
@@ -1354,7 +1354,7 @@ static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
rq->nr_uninterruptible--;

enqueue_task(rq, p, wakeup);
- inc_nr_running(p, rq);
+ inc_nr_running(rq);
}

/*
@@ -1366,7 +1366,7 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
rq->nr_uninterruptible++;

dequeue_task(rq, p, sleep);
- dec_nr_running(p, rq);
+ dec_nr_running(rq);
}

/**
@@ -2006,7 +2006,7 @@ void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
* management (if any):
*/
p->sched_class->task_new(rq, p);
- inc_nr_running(p, rq);
+ inc_nr_running(rq);
}
check_preempt_curr(rq, p);
#ifdef CONFIG_SMP
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 72e25c7..6c091d6 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -520,7 +520,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)

if (!initial) {
/* sleeps upto a single latency don't count. */
- if (sched_feat(NEW_FAIR_SLEEPERS) && entity_is_task(se))
+ if (sched_feat(NEW_FAIR_SLEEPERS))
vruntime -= sysctl_sched_latency;

/* ensure we never gain time by being placed backwards. */
@@ -1106,7 +1106,11 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
}

gran = sysctl_sched_wakeup_granularity;
- if (unlikely(se->load.weight != NICE_0_LOAD))
+ /*
+ * More easily preempt - nice tasks, while not making
+ * it harder for + nice tasks.
+ */
+ if (unlikely(se->load.weight > NICE_0_LOAD))
gran = calc_delta_fair(gran, &se->load);

if (pse->vruntime + gran < se->vruntime)
--
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