From 6faf72834d9d0c0dc6632604eaeffb621e87fcf9 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 13 May 2013 06:53:37 -0700 Subject: rcu: Fix comparison sense in rcu_needs_cpu() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit c0f4dfd4f (rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacks) introduced a bug that can result in excessively long grace periods. This bug reverse the senes of the "if" statement checking for lazy callbacks, so that RCU takes a lazy approach when there are in fact non-lazy callbacks. This can result in excessive boot, suspend, and resume times. This commit therefore fixes the sense of this "if" statement. Reported-by: Borislav Petkov Reported-by: Bjørn Mork Reported-by: Joerg Roedel Signed-off-by: Paul E. McKenney Tested-by: Bjørn Mork Tested-by: Joerg Roedel --- kernel/rcutree_plugin.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 170814d..6d939a6 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -1667,7 +1667,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj) rdtp->last_accelerate = jiffies; /* Request timer delay depending on laziness, and round. */ - if (rdtp->all_lazy) { + if (!rdtp->all_lazy) { *dj = round_up(rcu_idle_gp_delay + jiffies, rcu_idle_gp_delay) - jiffies; } else { -- cgit v1.1 From 615ee5443ff9bedd356dc6865f3e9c276ce434ea Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Tue, 26 Mar 2013 11:35:16 -0400 Subject: rcu: Don't allocate bootmem from rcu_init() When rcu_init() is called we already have slab working, allocating bootmem at that point results in warnings and an allocation from slab. This commit therefore changes alloc_bootmem_cpumask_var() to alloc_cpumask_var() in rcu_bootup_announce_oddness(), which is called from rcu_init(). Signed-off-by: Sasha Levin Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett Tested-by: Robin Holt [paulmck: convert to zalloc_cpumask_var(), as suggested by Yinghai Lu.] --- kernel/rcutree_plugin.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 6d939a6..3db5a37 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -88,7 +88,7 @@ static void __init rcu_bootup_announce_oddness(void) #ifdef CONFIG_RCU_NOCB_CPU #ifndef CONFIG_RCU_NOCB_CPU_NONE if (!have_rcu_nocb_mask) { - alloc_bootmem_cpumask_var(&rcu_nocb_mask); + zalloc_cpumask_var(&rcu_nocb_mask, GFP_KERNEL); have_rcu_nocb_mask = true; } #ifdef CONFIG_RCU_NOCB_CPU_ZERO -- cgit v1.1