[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <86802c440610222317l1867ab38v4c33231b96237b7f@mail.gmail.com>
Date: Sun, 22 Oct 2006 23:17:23 -0700
From: yhlu <yhlu.kernel@...il.com>
To: "Eric W. Biederman" <ebiederm@...ssion.com>
Cc: "Andi Kleen" <ak@...e.de>, "Muli Ben-Yehuda" <muli@...ibm.com>,
"Linux Kernel Mailing List" <linux-kernel@...r.kernel.org>,
"Andrew Morton" <akpm@...l.org>
Subject: Re: [PATCH 2/2] x86_64 irq: Only look at per_cpu data for online cpus.
On 10/22/06, Eric W. Biederman <ebiederm@...ssion.com> wrote:
>
> When I generalized __assign_irq_vector I failed to pay attention
> to what happens when you access a per cpu data structure for
> a cpu that is not online. It is an undefined case making any
> code that does it have undefined behavior as well.
>
> The code still needs to be able to allocate a vector across cpus
> that are not online to properly handle combinations like lowest
> priority interrupt delivery and cpu_hotplug. Not that we can do
> that today but the infrastructure shouldn't prevent it.
>
> So this patch updates the places where we touch per cpu data
> to only touch online cpus, it makes cpu vector allocation
> an atomic operation with respect to cpu hotplug, and it updates
> the cpu start code to properly initialize vector_irq so we
> don't have inconsistencies.
>
> Signed-off-by: Eric W. Biederman <ebiederm@...ssion.com>
Acked-by: Yinghai Lu <yinghai.lu@....com>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists