lkml.org 
[lkml]   [2012]   [Jan]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Is register_cpu() now obligatory?
On 01/08/2012 05:00 PM, Richard Weinberger wrote:
> Hi!
>
> In Linus' tree as of today UML is broken.
> It's crashing because get_cpu_device() in topology_add_dev()
> returns a device with an invalid kobj (address is 0x10).
>
> The code seems to assume that each arch has to register their CPUs
> using register_cpu().
>
> Is this a regression or was UML always faulty because it did not register it's CPU?

See Linus's comment yesterday:
https://lkml.org/lkml/2012/1/7/114


> The below patch fixes the issue for UML.
>
> Thanks,
> //richard
>
> ---
> diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
> index bc49474..f3b43fe 100644
> --- a/arch/um/kernel/Makefile
> +++ b/arch/um/kernel/Makefile
> @@ -12,7 +12,7 @@ clean-files :=
> obj-y = config.o exec.o exitcode.o init_task.o irq.o ksyms.o mem.o \
> physmem.o process.o ptrace.o reboot.o sigio.o \
> signal.o smp.o syscall.o sysrq.o time.o tlb.o trap.o \
> - um_arch.o umid.o skas/
> + um_arch.o umid.o cpu.o skas/
>
> obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
> obj-$(CONFIG_GPROF) += gprof_syms.o
> diff --git a/arch/um/kernel/cpu.c b/arch/um/kernel/cpu.c
> new file mode 100644
> index 0000000..4914df2
> --- /dev/null
> +++ b/arch/um/kernel/cpu.c
> @@ -0,0 +1,19 @@
> +#include <linux/init.h>
> +#include <linux/device.h>
> +#include <linux/cpu.h>
> +#include <linux/percpu.h>
> +
> +static DEFINE_PER_CPU(struct cpu, cpu_devices);
> +
> +static int __init topology_init(void)
> +{
> + int cpu;
> +
> + for_each_possible_cpu(cpu) {
> + struct cpu *c = &per_cpu(cpu_devices, cpu);
> + register_cpu(c, cpu);
> + }
> +
> + return 0;
> +}
> +subsys_initcall(topology_init);
>


--
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***


\
 
 \ /
  Last update: 2012-01-09 02:41    [W:0.052 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site