From 93ed80181e0ce7b81bc88a67fabad1ad829fc460 Mon Sep 17 00:00:00 2001

From: Frediano Ziglio <frediano.ziglio@citrix.com>

Date: Wed, 2 Jul 2014 12:59:34 +0100

Subject: [PATCH 1/1] Balance correctly IRQs reappearing

If IRQ disappears and reappears later (this happens frequently for Xen)

the IRQ is not balanced correctly due to overflow in irq_count (as the

counter got smaller and difference cause overflow).

Rescan if this happens fix the problem.

Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>

---

 procinterrupts.c | 8 ++++++++

 1 file changed, 8 insertions(+)

diff --git a/procinterrupts.c b/procinterrupts.c

index 6a6bdaa..3476473 100644

--- a/procinterrupts.c

+++ b/procinterrupts.c

@@ -181,6 +181,14 @@ void parse_proc_interrupts(void)

 			break;

 		}

+		/* IRQ removed and reinserted, need restart or this will

+		 * cause an overflow and IRQ won't be rebalanced again

+		 */

+		if (count < info->irq_count) {

+			need_rescan = 1;

+			break;

+		}

+

 		info->last_irq_count = info->irq_count;		

 		info->irq_count = count;

-- 

2.16.1