lkml.org 
[lkml]   [2016]   [May]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity
On Sun, May 22, 2016 at 09:00:01AM +0200, Mike Galbraith wrote:
> On Sat, 2016-05-21 at 21:00 +0200, Mike Galbraith wrote:
> > On Sat, 2016-05-21 at 16:04 +0200, Mike Galbraith wrote:
> >
> > > Wakees that were not migrated/normalized eat an unwanted min_vruntime,
> > > and likely take a size XXL latency hit. Big box running master bled
> > > profusely under heavy load until I turned TTWU_QUEUE off.
>
> May as well make it official and against master.today. Fly or die
> little patchlet.
>
> sched/fair: Move se->vruntime normalization state into struct sched_entity

Does this work?

---
include/linux/sched.h | 1 +
kernel/sched/core.c | 18 +++++++++++-------
2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1b43b45a22b9..a2001e01b3df 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1534,6 +1534,7 @@ struct task_struct {
unsigned sched_reset_on_fork:1;
unsigned sched_contributes_to_load:1;
unsigned sched_migrated:1;
+ unsigned sched_remote_wakeup:1;
unsigned :0; /* force alignment to the next boundary */

/* unserialized, strictly 'current' */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 404c0784b1fc..7f2cae4620c7 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1768,13 +1768,15 @@ void sched_ttwu_pending(void)
cookie = lockdep_pin_lock(&rq->lock);

while (llist) {
+ int wake_flags = 0;
+
p = llist_entry(llist, struct task_struct, wake_entry);
llist = llist_next(llist);
- /*
- * See ttwu_queue(); we only call ttwu_queue_remote() when
- * its a x-cpu wakeup.
- */
- ttwu_do_activate(rq, p, WF_MIGRATED, cookie);
+
+ if (p->sched_remote_wakeup)
+ wake_flags = WF_MIGRATED;
+
+ ttwu_do_activate(rq, p, wake_flags, cookie);
}

lockdep_unpin_lock(&rq->lock, cookie);
@@ -1819,10 +1821,12 @@ void scheduler_ipi(void)
irq_exit();
}

-static void ttwu_queue_remote(struct task_struct *p, int cpu)
+static void ttwu_queue_remote(struct task_struct *p, int cpu, int wake_flags)
{
struct rq *rq = cpu_rq(cpu);

+ p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED);
+
if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) {
if (!set_nr_if_polling(rq->idle))
smp_send_reschedule(cpu);
@@ -1869,7 +1873,7 @@ static void ttwu_queue(struct task_struct *p, int cpu, int wake_flags)
#if defined(CONFIG_SMP)
if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) {
sched_clock_cpu(cpu); /* sync clocks x-cpu */
- ttwu_queue_remote(p, cpu);
+ ttwu_queue_remote(p, cpu, wake_flags);
return;
}
#endif
\
 
 \ /
  Last update: 2016-05-23 11:41    [W:0.088 / U:0.960 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site