Hi to all, this fixed my issues with cgroups and RT_GROUP_SCHED. A big thanks to the RT maintainers, specially to Peter Zijlstra. This patch provides the best performance I ever experience while using RT_GROUP_SCHED! Thanks, Rolando > * Fix a long standing RT throttling problem with cgroups and > RT_GROUP_SCHED (Peter Zijlstra, Thanks to Carsten Emde for > providing the debug information!) On Wed, Oct 19, 2011 at 10:59 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote: > Dear RT Folks, > > I'm pleased to announce the 3.0.7-rt20 release. > > 3.0.7-rt19 is an not announced intermediate release, which only > updates to 3.0.7. No rt changes except dropping patches which made it > into 3.0.7. > > Changes from 3.0.7-rt19 to 3.0.7-rt20 > > * Fix a long standing RT throttling problem with cgroups and > RT_GROUP_SCHED (Peter Zijlstra, Thanks to Carsten Emde for > providing the debug information!) > > * Minor fixes (Yong Zhang) > > Delta patch against 3.0.7-rt19 > > https://tglx.de/~tglx/rt/patch-3.0.7-rt19-rt20.patch.gz > > also appended below. > > > Patch against 3.0.7 can be found here: > > https://tglx.de/~tglx/rt/patch-3.0.7-rt20.patch.gz > > > The split quilt queue is available at: > > https://tglx.de/~tglx/rt/patches-3.0.7-rt20.tar.gz > > Known issues: > > Yong discovered a non critical cpuhotplug problem, which needs some > more thought. Will try to address that in the next days as traveling > allows (about to head to Prague for a long RTLWS/KS/LinuxCon/ELCE > week). > > Enjoy, > > tglx > > ---------------> > Index: linux-2.6/kernel/cpu.c > =================================================================== > --- linux-2.6.orig/kernel/cpu.c > +++ linux-2.6/kernel/cpu.c > @@ -139,7 +139,7 @@ static int cpu_unplug_begin(unsigned int > struct task_struct *tsk; > > init_completion(&hp->synced); > - tsk = kthread_create(sync_unplug_thread, hp, "sync_unplug/%d\n", cpu); > + tsk = kthread_create(sync_unplug_thread, hp, "sync_unplug/%d", cpu); > if (IS_ERR(tsk)) > return (PTR_ERR(tsk)); > kthread_bind(tsk, cpu); > Index: linux-2.6/kernel/printk.c > =================================================================== > --- linux-2.6.orig/kernel/printk.c > +++ linux-2.6/kernel/printk.c > @@ -1282,8 +1282,8 @@ void printk_tick(void) > > int printk_needs_cpu(int cpu) > { > - if (cpu_is_offline(cpu)) > - printk_tick(); > + if (unlikely(cpu_is_offline(cpu))) > + __this_cpu_write(printk_pending, 0); > return __this_cpu_read(printk_pending); > } > > Index: linux-2.6/kernel/sched_rt.c > =================================================================== > --- linux-2.6.orig/kernel/sched_rt.c > +++ linux-2.6/kernel/sched_rt.c > @@ -556,12 +556,9 @@ static inline int balance_runtime(struct > > static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) > { > - int i, idle = 1; > + int i, idle = 1, throttled = 0; > const struct cpumask *span; > > - if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) > - return 1; > - > span = sched_rt_period_mask(); > for_each_cpu(i, span) { > int enqueue = 0; > @@ -596,12 +593,17 @@ static int do_sched_rt_period_timer(stru > if (!rt_rq_throttled(rt_rq)) > enqueue = 1; > } > + if (rt_rq->rt_throttled) > + throttled = 1; > > if (enqueue) > sched_rt_rq_enqueue(rt_rq); > raw_spin_unlock(&rq->lock); > } > > + if (!throttled && (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF)) > + return 1; > + > return idle; > } > > @@ -633,8 +635,24 @@ static int sched_rt_runtime_exceeded(str > return 0; > > if (rt_rq->rt_time > runtime) { > - rt_rq->rt_throttled = 1; > - printk_once(KERN_WARNING "sched: RT throttling activated\n"); > + struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); > + > + /* > + * Don't actually throttle groups that have no runtime assigned > + * but accrue some time due to boosting. > + */ > + if (likely(rt_b->rt_runtime)) { > + rt_rq->rt_throttled = 1; > + printk_once(KERN_WARNING "sched: RT throttling activated\n"); > + } else { > + /* > + * In case we did anyway, make it go away, > + * replenishment is a joke, since it will replenish us > + * with exactly 0 ns. > + */ > + rt_rq->rt_time = 0; > + } > + > if (rt_rq_throttled(rt_rq)) { > sched_rt_rq_dequeue(rt_rq); > return 1; > @@ -662,7 +680,8 @@ static void update_curr_rt(struct rq *rq > if (unlikely((s64)delta_exec < 0)) > delta_exec = 0; > > - schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec)); > + schedstat_set(curr->se.statistics.exec_max, > + max(curr->se.statistics.exec_max, delta_exec)); > > curr->se.sum_exec_runtime += delta_exec; > account_group_exec_runtime(curr, delta_exec); > Index: linux-2.6/kernel/workqueue.c > =================================================================== > --- linux-2.6.orig/kernel/workqueue.c > +++ linux-2.6/kernel/workqueue.c > @@ -3274,14 +3274,14 @@ static void flush_gcwq(struct global_cwq > > spin_unlock_irq(&gcwq->lock); > > - gcwq = get_gcwq(get_cpu()); > + gcwq = get_gcwq(get_cpu_light()); > spin_lock_irq(&gcwq->lock); > list_for_each_entry_safe(work, nw, &non_affine_works, entry) { > list_del_init(&work->entry); > ___queue_work(get_work_cwq(work)->wq, gcwq, work); > } > spin_unlock_irq(&gcwq->lock); > - put_cpu(); > + put_cpu_light(); > } > > static int __devinit workqueue_cpu_down_callback(struct notifier_block *nfb, > Index: linux-2.6/localversion-rt > =================================================================== > --- linux-2.6.orig/localversion-rt > +++ linux-2.6/localversion-rt > @@ -1 +1 @@ > --rt19 > +-rt20 > -- > To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
