From: julien.grall@citrix•com (Julien Grall)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 3/3] xen/arm: don't try to re-register vcpu_info on cpu_hotplug.
Date: Wed, 14 Oct 2015 23:32:45 +0100 [thread overview]
Message-ID: <561ED80D.9020905@citrix.com> (raw)
In-Reply-To: <1444844997-27314-3-git-send-email-stefano.stabellini@eu.citrix.com>
Hi Stefano,
On 14/10/2015 18:49, Stefano Stabellini wrote:
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu•citrix.com>
> ---
> arch/arm/xen/enlighten.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> index 6c09cc4..59f5421 100644
> --- a/arch/arm/xen/enlighten.c
> +++ b/arch/arm/xen/enlighten.c
> @@ -93,6 +93,12 @@ static void xen_percpu_init(void)
> int err;
> int cpu = get_cpu();
>
> + /* vcpu_info already registered, can happen with cpu-hotplug */
Can you please add more comment and explain in the commit message why
this is necessary for cpu-hotplug?
I had to look at the x86 code to fully understand that it's not possible
to call VCPUOP_register_vcpu_info twice because there is no hypercall to
remove the vcpu shared page.
> + if (per_cpu(xen_vcpu, cpu) != NULL) {
> + put_cpu();
> + return;
> + }
> +
> pr_info("Xen: initializing cpu%d\n", cpu);
> vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
>
>
Regards,
--
Julien Grall
next prev parent reply other threads:[~2015-10-14 22:32 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-14 17:49 xen,arm: enable cpu_hotplug Stefano Stabellini
2015-10-14 17:49 ` [PATCH 1/3] xen/arm: Enable cpu_hotplug.c Stefano Stabellini
2015-10-14 18:05 ` [Xen-devel] " Konrad Rzeszutek Wilk
2015-10-14 18:17 ` Stefano Stabellini
2015-10-16 15:21 ` Stefano Stabellini
2015-10-14 22:51 ` Julien Grall
2015-10-16 15:23 ` Stefano Stabellini
2015-10-14 17:49 ` [PATCH 2/3] xen, cpu_hotplug: call device_offline instead of cpu_down Stefano Stabellini
2015-10-14 17:49 ` [PATCH 3/3] xen/arm: don't try to re-register vcpu_info on cpu_hotplug Stefano Stabellini
2015-10-14 22:32 ` Julien Grall [this message]
2015-10-16 15:31 ` Stefano Stabellini
2015-10-14 23:23 ` xen,arm: enable cpu_hotplug Julien Grall
2015-10-15 8:39 ` [Xen-devel] " Ian Campbell
2015-10-15 9:57 ` Julien Grall
2015-10-15 9:58 ` Julien Grall
2015-10-16 15:44 ` Stefano Stabellini
2015-10-16 15:41 ` Stefano Stabellini
2015-10-16 15:45 ` Julien Grall
2015-10-16 15:45 ` Stefano Stabellini
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