From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir@xen.org>
Subject: Re: [PATCH] x86: fix off-by-one in nr_irqs_gsi
 calculation
Date: Thu, 26 Jul 2012 16:31:07 +0100
Message-ID: <CC37214B.46B60%keir@xen.org>
References: <501179280200007800090A72@nat28.tlf.novell.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <501179280200007800090A72@nat28.tlf.novell.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Jan Beulich <JBeulich@suse.com>, xen-devel <xen-devel@lists.xen.org>
List-Id: xen-devel@lists.xenproject.org

On 26/07/2012 16:06, "Jan Beulich" <JBeulich@suse.com> wrote:

> highest_gsi() returns the last valid GSI, not a count.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Why not "nr_irqs_gsi = max(nr_irqs_gsi, highest_gsi()+1)"?

> --- a/xen/arch/x86/io_apic.c
> +++ b/xen/arch/x86/io_apic.c
> @@ -2531,7 +2531,9 @@ void __init init_ioapic_mappings(void)
>          }
>      }
>  
> -    nr_irqs_gsi = max(nr_irqs_gsi, highest_gsi());
> +    i = highest_gsi();
> +    if ( i >= nr_irqs_gsi )
> +        nr_irqs_gsi = i + 1;
>  
>      if ( max_gsi_irqs == 0 )
>          max_gsi_irqs = nr_irqs ? nr_irqs / 8 : PAGE_SIZE;
> 
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel