Re: [PATCH]gx-suspmod.c use boot_cpu_data instead ofcurrent_cpu_data

From: Andrew Morton
Date: Wed Jul 25 2007 - 02:41:42 EST


On Wed, 25 Jul 2007 14:19:05 +0000 Dave Young <hidave.darkstar@xxxxxxxxx> wrote:

> Hi,
> in preemptible kernel will report BUG: using smp_processor_id() in preemptible, so use boot_cpu_data instead of current_cpu_data.
>
> Signed-off-by: Dave Young <hidave.darkstar@xxxxxxxxx>
>
> ---
> arch/i386/kernel/cpu/cpufreq/gx-suspmod.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff -pur linux/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c linux.new/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c
> --- linux/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c 2007-07-25 14:11:06.000000000 +0000
> +++ linux.new/arch/i386/kernel/cpu/cpufreq/gx-suspmod.c 2007-07-25 13:57:29.000000000 +0000
> @@ -181,8 +181,8 @@ static __init struct pci_dev *gx_detect_
> struct pci_dev *gx_pci = NULL;
>
> /* check if CPU is a MediaGX or a Geode. */
> - if ((current_cpu_data.x86_vendor != X86_VENDOR_NSC) &&
> - (current_cpu_data.x86_vendor != X86_VENDOR_CYRIX)) {
> + if ((boot_cpu_data.x86_vendor != X86_VENDOR_NSC) &&
> + (boot_cpu_data.x86_vendor != X86_VENDOR_CYRIX)) {
> dprintk("error: no MediaGX/Geode processor found!\n");
> return NULL;
> }

um, I suspect it really wants to get at the current CPU. But putting a
preempt_disable() around just that code is meaningless: the current CPU
could change immediately before or after the code block. It needs deeper
fixing, methinks.

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