From d9a3da0699b24a589b27a61e1a5b5bd30d9db669 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 2 Dec 2009 12:10:15 -0800 Subject: rcu: Add expedited grace-period support for preemptible RCU Implement an synchronize_rcu_expedited() for preemptible RCU that actually is expedited. This uses synchronize_sched_expedited() to force all threads currently running in a preemptible-RCU read-side critical section onto the appropriate ->blocked_tasks[] list, then takes a snapshot of all of these lists and waits for them to drain. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1259784616158-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutree.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'kernel/rcutree.c') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index d47e03e..53ae959 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -948,7 +948,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) { unsigned long flags; unsigned long mask; - int need_quiet = 0; + int need_report = 0; struct rcu_data *rdp = rsp->rda[cpu]; struct rcu_node *rnp; @@ -967,7 +967,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) break; } if (rnp == rdp->mynode) - need_quiet = rcu_preempt_offline_tasks(rsp, rnp, rdp); + need_report = rcu_preempt_offline_tasks(rsp, rnp, rdp); else spin_unlock(&rnp->lock); /* irqs remain disabled. */ mask = rnp->grpmask; @@ -982,10 +982,12 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) */ spin_unlock(&rsp->onofflock); /* irqs remain disabled. */ rnp = rdp->mynode; - if (need_quiet) + if (need_report & RCU_OFL_TASKS_NORM_GP) rcu_report_unblock_qs_rnp(rnp, flags); else spin_unlock_irqrestore(&rnp->lock, flags); + if (need_report & RCU_OFL_TASKS_EXP_GP) + rcu_report_exp_rnp(rsp, rnp); rcu_adopt_orphan_cbs(rsp); } @@ -1843,6 +1845,8 @@ static void __init rcu_init_one(struct rcu_state *rsp) rnp->level = i; INIT_LIST_HEAD(&rnp->blocked_tasks[0]); INIT_LIST_HEAD(&rnp->blocked_tasks[1]); + INIT_LIST_HEAD(&rnp->blocked_tasks[2]); + INIT_LIST_HEAD(&rnp->blocked_tasks[3]); } } } -- cgit v1.1