WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] [PATCH 14/17] xen: dynamically allocate irq & event structur

To: "H. Peter Anvin" <hpa@xxxxxxxxx>
Subject: [Xen-devel] [PATCH 14/17] xen: dynamically allocate irq & event structures
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Fri, 13 Mar 2009 09:42:35 -0700
Cc: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, the arch/x86 maintainers <x86@xxxxxxxxxx>, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>, Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Delivery-date: Fri, 13 Mar 2009 09:55:36 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <1236962558-13748-1-git-send-email-jeremy@xxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <1236962558-13748-1-git-send-email-jeremy@xxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>

Impact: reduce memory usage

Dynamically allocate the irq_info and evtchn_to_irq arrays, so that
1) the irq_info array scales to the actual number of possible irqs,
and 2) we don't needlessly increase the static size of the kernel
when we aren't running under Xen.

Derived on patch from Mike Travis <travis@xxxxxxx>.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 drivers/xen/events.c |   15 +++++++++------
 1 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 3cf0a1b..e8f08c0 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -27,6 +27,7 @@
 #include <linux/module.h>
 #include <linux/string.h>
 #include <linux/bootmem.h>
+#include <linux/irqnr.h>
 
 #include <asm/ptrace.h>
 #include <asm/irq.h>
@@ -91,11 +92,9 @@ struct irq_info
 };
 #define PIRQ_NEEDS_EOI (1 << 0)
 
-static struct irq_info irq_info[NR_IRQS];
+static struct irq_info *irq_info;
 
-static int evtchn_to_irq[NR_EVENT_CHANNELS] = {
-       [0 ... NR_EVENT_CHANNELS-1] = -1
-};
+static int *evtchn_to_irq;
 struct cpu_evtchn_s {
        unsigned long bits[NR_EVENT_CHANNELS/BITS_PER_LONG];
 };
@@ -509,7 +508,7 @@ static int find_irq_by_gsi(unsigned gsi)
 {
        int irq;
 
-       for(irq = 0; irq < NR_IRQS; irq++) {
+       for(irq = 0; irq < nr_irqs; irq++) {
                struct irq_info *info = info_for_irq(irq);
 
                if (info == NULL || info->type != IRQT_PIRQ)
@@ -1174,7 +1173,11 @@ void __init xen_init_IRQ(void)
        size_t size = nr_cpu_ids * sizeof(struct cpu_evtchn_s);
 
        cpu_evtchn_mask_p = alloc_bootmem(size);
-       BUG_ON(cpu_evtchn_mask_p == NULL);
+       irq_info = alloc_bootmem(nr_irqs * sizeof(*irq_info));
+
+       evtchn_to_irq = alloc_bootmem(NR_EVENT_CHANNELS * 
sizeof(*evtchn_to_irq));
+       for(i = 0; i < NR_EVENT_CHANNELS; i++)
+               evtchn_to_irq[i] = -1;
 
        init_evtchn_cpu_bindings();
 
-- 
1.6.0.6


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel