[PATCH] rcu: fix hotplug-cpu ->donelist leak

[Oleg Nesterov]

Pointed out by Srivatsa Vaddagiri <vatsa@xxxxxxxxxx>.

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@xxxxxxxxxx>

--- 2.6.15/kernel/rcupdate.c~4_HPFIX	2006-01-10 19:06:38.000000000 +0300
+++ 2.6.15/kernel/rcupdate.c	2006-01-10 19:15:01.000000000 +0300
@@ -343,8 +343,9 @@ static void __rcu_offline_cpu(struct rcu
 	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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