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[Xen-devel] [PATCH 1/2] xen: events: do not workaround too-small nr_irqs

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] [PATCH 1/2] xen: events: do not workaround too-small nr_irqs
From: Ian Campbell <ian.campbell@xxxxxxxxxx>
Date: Wed, 9 Feb 2011 11:10:44 +0000
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>, Ian Campbell <ian.campbell@xxxxxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Delivery-date: Wed, 09 Feb 2011 03:11:34 -0800
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This workaround was somewhat useful prior to the introduction of the
core irq allocator and 026c9d2d0d75 "xen: events: allocate GSIs and
dynamic IRQs from separate IRQ ranges." but should not be unnecessary now.

If nr_irqs turns out to be too small under Xen then we use (or define
if necessary) the interfaces to increase nr_irqs rather than working
around the core allocator in this way.

In my configuration NR_IRQS ends up being 2304 with nr_irq_gsi 272
which is sufficient.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
---
 drivers/xen/events.c |    7 -------
 1 files changed, 0 insertions(+), 7 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 975e90f..ce33061 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -393,15 +393,8 @@ static int xen_allocate_irq_dynamic(void)
                first = get_nr_irqs_gsi();
 #endif
 
-retry:
        irq = irq_alloc_desc_from(first, -1);
 
-       if (irq == -ENOMEM && first > NR_IRQS_LEGACY) {
-               printk(KERN_ERR "Out of dynamic IRQ space and eating into GSI 
space. You should increase nr_irqs\n");
-               first = max(NR_IRQS_LEGACY, first - NR_IRQS_LEGACY);
-               goto retry;
-       }
-
        if (irq < 0)
                panic("No available IRQ to bind to: increase nr_irqs!\n");
 
-- 
1.5.6.5


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