From 5b61b0baa9e80289c53413e573befc5790a04ac7 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Fri, 19 Aug 2011 11:39:11 -0700 Subject: [PATCH] rcu: Wire up RCU_BOOST_PRIO for rcutree RCU boost threads start life at RCU_BOOST_PRIO, while others remain at RCU_KTHREAD_PRIO. While here, change thread names to match other kthreads, and adjust rcu_yield() to not override the priority set by the user. This last change sets the stage for runtime changes to priority in the -rt tree. Signed-off-by: Mike Galbraith Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 2 -- kernel/rcutree_plugin.h | 20 +++++++++++++++----- 2 files changed, 15 insertions(+), 7 deletions(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index c95fa89ffef9..8455043c9250 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -131,8 +131,6 @@ static void rcu_node_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu); static void invoke_rcu_core(void); static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp); -#define RCU_KTHREAD_PRIO 1 /* RT priority for per-CPU kthreads. */ - /* * Track the rcutorture test sequence number and the update version * number within a given test. The rcutorture_testseq is incremented diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 28422767d854..b4cbe5bf2326 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -27,6 +27,14 @@ #include #include +#define RCU_KTHREAD_PRIO 1 + +#ifdef CONFIG_RCU_BOOST +#define RCU_BOOST_PRIO CONFIG_RCU_BOOST_PRIO +#else +#define RCU_BOOST_PRIO RCU_KTHREAD_PRIO +#endif + /* * Check the RCU kernel configuration parameters and print informative * messages about anything out of the ordinary. If you like #ifdef, you @@ -1364,13 +1372,13 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, if (rnp->boost_kthread_task != NULL) return 0; t = kthread_create(rcu_boost_kthread, (void *)rnp, - "rcub%d", rnp_index); + "rcub/%d", rnp_index); if (IS_ERR(t)) return PTR_ERR(t); raw_spin_lock_irqsave(&rnp->lock, flags); rnp->boost_kthread_task = t; raw_spin_unlock_irqrestore(&rnp->lock, flags); - sp.sched_priority = RCU_KTHREAD_PRIO; + sp.sched_priority = RCU_BOOST_PRIO; sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); wake_up_process(t); /* get to TASK_INTERRUPTIBLE quickly. */ return 0; @@ -1465,6 +1473,7 @@ static void rcu_yield(void (*f)(unsigned long), unsigned long arg) { struct sched_param sp; struct timer_list yield_timer; + int prio = current->rt_priority; setup_timer_on_stack(&yield_timer, f, arg); mod_timer(&yield_timer, jiffies + 2); @@ -1472,7 +1481,8 @@ static void rcu_yield(void (*f)(unsigned long), unsigned long arg) sched_setscheduler_nocheck(current, SCHED_NORMAL, &sp); set_user_nice(current, 19); schedule(); - sp.sched_priority = RCU_KTHREAD_PRIO; + set_user_nice(current, 0); + sp.sched_priority = prio; sched_setscheduler_nocheck(current, SCHED_FIFO, &sp); del_timer(&yield_timer); } @@ -1591,7 +1601,7 @@ static int __cpuinit rcu_spawn_one_cpu_kthread(int cpu) t = kthread_create_on_node(rcu_cpu_kthread, (void *)(long)cpu, cpu_to_node(cpu), - "rcuc%d", cpu); + "rcuc/%d", cpu); if (IS_ERR(t)) return PTR_ERR(t); if (cpu_online(cpu)) @@ -1700,7 +1710,7 @@ static int __cpuinit rcu_spawn_one_node_kthread(struct rcu_state *rsp, return 0; if (rnp->node_kthread_task == NULL) { t = kthread_create(rcu_node_kthread, (void *)rnp, - "rcun%d", rnp_index); + "rcun/%d", rnp_index); if (IS_ERR(t)) return PTR_ERR(t); raw_spin_lock_irqsave(&rnp->lock, flags); -- 2.39.5