Re: [Xen-devel] [PATCH] xen: disable PV spinlocks on HVM

From: Konrad Rzeszutek Wilk
Date: Tue Sep 06 2011 - 13:03:29 EST


On Tue, Sep 06, 2011 at 05:41:47PM +0100, stefano.stabellini@xxxxxxxxxxxxx wrote:
> From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
>
> PV spinlocks cannot possibly work with the current code because they are
> enabled after pvops patching has already been done, and because PV
> spinlocks use a different data structure than native spinlocks so we
> cannot switch between them dynamically. A spinlock that has been taken
> once by the native code (__ticket_spin_lock) cannot be taken by
> __xen_spin_lock even after it has been released.

Let me stick it on my 3.1-rc5 bug-fix list and add stable@xxxxxxxxxx to it.

Stefan, if you have some time this week, and can test it - I can also
stick 'Tested-by' if you would like.

Thinking to send the patches on Friday.

>
> Reported-by: Stefan Bader <stefan.bader@xxxxxxxxxxxxx>
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> ---
> arch/x86/xen/smp.c | 1 -
> 1 files changed, 0 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
> index e79dbb9..51339b4 100644
> --- a/arch/x86/xen/smp.c
> +++ b/arch/x86/xen/smp.c
> @@ -522,7 +522,6 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
> WARN_ON(xen_smp_intr_init(0));
>
> xen_init_lock_cpu(0);
> - xen_init_spinlocks();
> }
>
> static int __cpuinit xen_hvm_cpu_up(unsigned int cpu)
> --
> 1.7.2.3
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/