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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2008-08-21 06:14:55 -0700
committerIngo Molnar <mingo@elte.hu>2008-08-21 16:01:02 +0200
commit275a89bdd3868af3008852594d2e169eaf69441b (patch)
tree81ad2537fe871a3e583013dabf6fdba539773332
parent0c925d79234fe77589d8ff3861f9f8bb9e7fc3f6 (diff)
rcu: use irq-safe locks
Some earlier tip/core/rcu patches caused RCU to incorrectly enable irqs too early in boot. This caused Yinghai's repeated-kexec testing to hit oopses, presumably due to so that device interrupts left over from the prior kernel instance (which would oops the newly booting kernel before it got a chance to reset said devices). This patch therefore converts all the local_irq_disable()s in rcuclassic.c to local_irq_save(). Besides, I never did like local_irq_disable() anyway. ;-) Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/rcuclassic.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c
index 01e761a6b38..3f6918966bd 100644
--- a/kernel/rcuclassic.c
+++ b/kernel/rcuclassic.c
@@ -247,6 +247,7 @@ static inline void raise_rcu_softirq(void)
*/
static void rcu_do_batch(struct rcu_data *rdp)
{
+ unsigned long flags;
struct rcu_head *next, *list;
int count = 0;
@@ -261,9 +262,9 @@ static void rcu_do_batch(struct rcu_data *rdp)
}
rdp->donelist = list;
- local_irq_disable();
+ local_irq_save(flags);
rdp->qlen -= count;
- local_irq_enable();
+ local_irq_restore(flags);
if (rdp->blimit == INT_MAX && rdp->qlen <= qlowmark)
rdp->blimit = blimit;
@@ -464,12 +465,14 @@ static void rcu_check_quiescent_state(struct rcu_ctrlblk *rcp,
static void rcu_move_batch(struct rcu_data *this_rdp, struct rcu_head *list,
struct rcu_head **tail, long batch)
{
+ unsigned long flags;
+
if (list) {
- local_irq_disable();
+ local_irq_save(flags);
this_rdp->batch = batch;
*this_rdp->nxttail[2] = list;
this_rdp->nxttail[2] = tail;
- local_irq_enable();
+ local_irq_restore(flags);
}
}
@@ -521,10 +524,11 @@ static void rcu_offline_cpu(int cpu)
static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp,
struct rcu_data *rdp)
{
+ unsigned long flags;
long completed_snap;
if (rdp->nxtlist) {
- local_irq_disable();
+ local_irq_save(flags);
completed_snap = ACCESS_ONCE(rcp->completed);
/*
@@ -554,7 +558,7 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp,
rdp->nxttail[0] = &rdp->nxtlist;
}
- local_irq_enable();
+ local_irq_restore(flags);
if (rcu_batch_after(rdp->batch, rcp->pending)) {
unsigned long flags;