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From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Vijay Kilari <vijay.kilari@gmail.com>,
	Ian Campbell <Ian.Campbell@citrix.com>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: manish.jaggi@caviumnetworks.com,
	Julien Grall <julien.grall@linaro.org>,
	Stefano Stabellini <stefano.stabellini@citrix.com>,
	"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
Subject: Re: Query: Boot time allocation of irq descriptors
Date: Wed, 11 Feb 2015 14:55:51 +0000	[thread overview]
Message-ID: <54DB6D77.1030004@citrix.com> (raw)
In-Reply-To: <CALicx6vO4FKuHXV2XbBkY0RQDSQnCSvFZdEvpTJUvkcBkeyrEw@mail.gmail.com>

On 11/02/15 14:50, Vijay Kilari wrote:
> Hi ,
>
>   I just glaced at the x86 code, here nr_irqs are set to 1024, which includes
> normal irq's and MSI's. Memory for these descriptors are allocated at boot time.
> is it correct?
>
> int __init init_irq_data(void)
> {
>
> ...
>     for (vector = 0; vector < NR_VECTORS; ++vector)
>         this_cpu(vector_irq)[vector] = INT_MIN;
>
>     irq_desc = xzalloc_array(struct irq_desc, nr_irqs);
>
> ...
> }
>
>
> In xen/include/asm-x86/irq.h
>
> #define MSI_IRQ(irq)       ((irq) >= nr_irqs_gsi && (irq) < nr_irqs)

What do you think is incorrect about it?

~Andrew

  reply	other threads:[~2015-02-11 14:55 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-11 14:50 Query: Boot time allocation of irq descriptors Vijay Kilari
2015-02-11 14:55 ` Andrew Cooper [this message]
2015-02-11 15:03   ` Vijay Kilari
2015-02-11 15:08     ` Jan Beulich
2015-02-11 15:05 ` Jan Beulich

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