From: Julien Grall <julien.grall@linaro.org>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>,
linux-kernel@vger.kernel.org, konrad.wilk@oracle.com,
boris.ostrovsky@oracle.com, xen-devel@lists.xenproject.org,
ian.campbell@citrix.com, patches@linaro.org
Subject: Re: [PATCH] xen/events: xen_evtchn_fifo_init can be called very late
Date: Tue, 28 Jan 2014 14:36:31 +0000 [thread overview]
Message-ID: <52E7C06F.3010205@linaro.org> (raw)
In-Reply-To: <alpine.DEB.2.02.1401281406090.4373@kaball.uk.xensource.com>
On 01/28/2014 02:30 PM, Stefano Stabellini wrote:
> On Tue, 28 Jan 2014, David Vrabel wrote:
>> On 28/01/14 00:34, Julien Grall wrote:
>>> On ARM, xen_init_IRQ (which calls xen_evtchn_fifo_init) is called after
>>> all CPUs are online. It would mean that the notifier will never be called.
>>
>> Why does ARM call xen_init_IRQ() so late? Is it possible to call it
>> earlier when only the boot CPU is online? There are problems with
>> attempting to init FIFO event channels after all CPUs are online.
>>
>> If evtchn_fifo_init_control_block(cpu) fails on anything other than the
>> first CPU, that CPU will be unable to receive any events. Xen will have
>> been switched to FIFO mode and it is not possible to revert back to
>> 2-level mode.
>
> We simply didn't need to be called that early.
> Most of xen_guest_init could be moved to an early_initcall, if that is
> necessary.
>
I'm actually working on a patch to move xen_init_IRQ() in early_initcall.
--
Julien Grall
next prev parent reply other threads:[~2014-01-28 14:36 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-28 0:34 [PATCH] xen/events: xen_evtchn_fifo_init can be called very late Julien Grall
2014-01-28 10:35 ` David Vrabel
2014-01-28 10:35 ` David Vrabel
2014-01-28 14:30 ` Stefano Stabellini
2014-01-28 14:36 ` Julien Grall [this message]
2014-01-28 14:36 ` Julien Grall
2014-01-28 14:30 ` Stefano Stabellini
-- strict thread matches above, loose matches on Subject: below --
2014-01-28 0:34 Julien Grall
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