From d7d6a11e8609f0319d4a2d8ede348f8b3374b652 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 21 Aug 2012 15:00:05 -0700 Subject: rcu: Simplify quiescent-state detection The current quiescent-state detection algorithm is needlessly complex. It records the grace-period number corresponding to the quiescent state at the time of the quiescent state, which works, but it seems better to simply erase any record of previous quiescent states at the time that the CPU notices the new grace period. This has the further advantage of removing another piece of RCU for which lockless reasoning is required. Therefore, this commit makes this change. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- kernel/rcutree_plugin.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/rcutree_plugin.h') diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index b4e8eb24a5f..4734afbea73 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -137,8 +137,6 @@ static void rcu_preempt_qs(int cpu) { struct rcu_data *rdp = &per_cpu(rcu_preempt_data, cpu); - rdp->passed_quiesce_gpnum = rdp->gpnum; - barrier(); if (rdp->passed_quiesce == 0) trace_rcu_grace_period("rcu_preempt", rdp->gpnum, "cpuqs"); rdp->passed_quiesce = 1; -- cgit v1.2.3