From 6260f6427c944279f8aca108140db900699a30de Mon Sep 17 00:00:00 2001
From: Pingfan Liu <kernelfans@gmail.com>
Date: Fri, 22 Apr 2022 18:02:12 +0800
Subject: [PATCH] s390/irq: utilize RCU instead of irq_lock_sparse() in
show_msi_interrupt()
As demonstrated by commit 74bdf7815dfb ("genirq: Speedup
show_interrupts()"), irq_desc can be accessed safely in RCU read section.
Hence here resorting to rcu read lock to get rid of irq_lock_sparse().
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Link: https://lore.kernel.org/r/20220422100212.22666-1-kernelfans@gmail.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
arch/s390/kernel/irq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index 3033f616e2569..45393919fe615 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -205,7 +205,7 @@ static void show_msi_interrupt(struct seq_file *p, int irq)
unsigned long flags;
int cpu;
- irq_lock_sparse();
+ rcu_read_lock();
desc = irq_to_desc(irq);
if (!desc)
goto out;
@@ -224,7 +224,7 @@ static void show_msi_interrupt(struct seq_file *p, int irq)
seq_putc(p, '\n');
raw_spin_unlock_irqrestore(&desc->lock, flags);
out:
- irq_unlock_sparse();
+ rcu_read_unlock();
}
/*