From 10b888d6cec2688e65e9e128b14bf98ecd199da2 Mon Sep 17 00:00:00 2001
From: Yinghai Lu <yinghai@kernel.org>
Date: Sat, 31 Jan 2009 14:50:07 -0800
Subject: [PATCH] irq, x86: fix lock status with numa_migrate_irq_desc
Eric Paris reported:
> I have an hp dl785g5 which is unable to successfully run
> 2.6.29-0.66.rc3.fc11.x86_64 or 2.6.29-rc2-next-20090126. During bootup
> (early in userspace daemons starting) I get the below BUG, which quickly
> renders the machine dead. I assume it is because sparse_irq_lock never
> gets released when the BUG kills that task.
Adjust lock sequence when migrating a descriptor with
CONFIG_NUMA_MIGRATE_IRQ_DESC enabled.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/io_apic.c | 5 +++--
kernel/irq/numa_migrate.c | 7 ++++++-
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index 1c4a1302536c6..9b0c480c383bf 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -2528,14 +2528,15 @@ static void irq_complete_move(struct irq_desc **descp)
vector = ~get_irq_regs()->orig_ax;
me = smp_processor_id();
+
+ if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain)) {
#ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
*descp = desc = move_irq_desc(desc, me);
/* get the new one */
cfg = desc->chip_data;
#endif
-
- if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain))
send_cleanup_vector(cfg);
+ }
}
#else
static inline void irq_complete_move(struct irq_desc **descp) {}
diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
index ecf765c6a77ac..acd88356ac76a 100644
--- a/kernel/irq/numa_migrate.c
+++ b/kernel/irq/numa_migrate.c
@@ -71,7 +71,7 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
desc = irq_desc_ptrs[irq];
if (desc && old_desc != desc)
- goto out_unlock;
+ goto out_unlock;
node = cpu_to_node(cpu);
desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
@@ -84,10 +84,15 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
init_copy_one_irq_desc(irq, old_desc, desc, cpu);
irq_desc_ptrs[irq] = desc;
+ spin_unlock_irqrestore(&sparse_irq_lock, flags);
/* free the old one */
free_one_irq_desc(old_desc, desc);
+ spin_unlock(&old_desc->lock);
kfree(old_desc);
+ spin_lock(&desc->lock);
+
+ return desc;
out_unlock:
spin_unlock_irqrestore(&sparse_irq_lock, flags);
--
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