From a9c828155ae8d1a1576f9648cc4d9677aea53f89 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Tue, 10 Jan 2006 17:24:53 +0300
Subject: [PATCH] [PATCH] rcu: fix hotplug-cpu ->donelist leak

Pointed out by Srivatsa Vaddagiri <vatsa@in.ibm.com>.

rcu_do_batch() stops after processing maxbatch callbacks
on ->donelist leaving rcu_tasklet in TASKLET_STATE_SCHED
state.

If CPU_DEAD event happens remaining ->donelist entries are
lost, rcu_offline_cpu() kills this tasklet.

With this patch ->donelist migrates along with ->curlist
and ->nxtlist to the current cpu.

Compile tested.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 kernel/rcupdate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index e18f9190eafa1..0cf8146bd5859 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -343,8 +343,9 @@ static void __rcu_offline_cpu(struct rcu_data *this_rdp,
 	spin_unlock_bh(&rcp->lock);
 	rcu_move_batch(this_rdp, rdp->curlist, rdp->curtail);
 	rcu_move_batch(this_rdp, rdp->nxtlist, rdp->nxttail);
-
+	rcu_move_batch(this_rdp, rdp->donelist, rdp->donetail);
 }
+
 static void rcu_offline_cpu(int cpu)
 {
 	struct rcu_data *this_rdp = &get_cpu_var(rcu_data);
-- 
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