From 0697a6c28e520ef4ce3ce9b7532e4374d47be90c Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 7 Aug 2011 20:26:31 -0700 Subject: [PATCH] rcu: Prohibit grace periods during early boot Greater use of RCU during early boot (before the scheduler is operating) is causing RCU to attempt to start grace periods during that time, which in turn is resulting in both RCU and the callback functions attempting to use the scheduler before it is ready. This commit prevents these problems by prohibiting RCU grace periods until after the scheduler has spawned the first non-idle task. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 3fdb61014c02..309c84da413a 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -842,8 +842,11 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) struct rcu_data *rdp = this_cpu_ptr(rsp->rda); struct rcu_node *rnp = rcu_get_root(rsp); - if (!cpu_needs_another_gp(rsp, rdp) || rsp->fqs_active) { - if (cpu_needs_another_gp(rsp, rdp)) + if (!rcu_scheduler_fully_active || + !cpu_needs_another_gp(rsp, rdp) || + rsp->fqs_active) { + if (rcu_scheduler_fully_active && + cpu_needs_another_gp(rsp, rdp)) rsp->fqs_need_gp = 1; if (rnp->completed == rsp->completed) { raw_spin_unlock_irqrestore(&rnp->lock, flags); -- 2.39.5