Hi,
Just a couple of nitpicks below. It's also common to prefix the patch
subject with the subsystem (i.e. "ARM: kexec: ...")
-Olof
On Wed, Nov 24, 2010 at 09:28:28AM +0100, Per Fransson wrote:
> v2 changes:
> * the interrupts of the calling core are no longer disabled
> before performing the IPI
> ---
>
> When kexec is used to start a crash kernel the other cores
> are notified. These non-crashing cores will save their state
> in the crash notes and then do nothing.
>
> Signed-off-by: Per Fransson <per.xx.fransson at stericsson.com>
> ---
> arch/arm/kernel/machine_kexec.c | 27 +++++++++++++++++++++++++++
> 1 files changed, 27 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c
> index 3a8fd51..57a7f2f 100644
> --- a/arch/arm/kernel/machine_kexec.c
> +++ b/arch/arm/kernel/machine_kexec.c
> @@ -23,6 +23,8 @@ extern unsigned long kexec_indirection_page;
> extern unsigned long kexec_mach_type;
> extern unsigned long kexec_boot_atags;
>
> +static atomic_t waiting_for_crash_ipi;
> +
> /*
> * Provide a dummy crash_notes definition while crash dump arrives to arm.
> * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
> @@ -37,9 +39,34 @@ void machine_kexec_cleanup(struct kimage *image)
> {
> }
>
> +void machine_crash_nonpanic_core(void *unused)
> +{
> + struct pt_regs regs;
> +
> + crash_setup_regs(®s, NULL);
> + printk(KERN_EMERG "CPU %u will stop doing anything useful since another CPU has crashed\n",
> + smp_processor_id());
No other architecture has verbose output like this. Maybe lower it to
KERN_DEBUG if you feel it's needed on a production kernel?
> + crash_save_cpu(®s, smp_processor_id());
> + flush_cache_all();
> +
> + atomic_dec(&waiting_for_crash_ipi);
> + while (1)
> + cpu_relax();
> +}
> +
> void machine_crash_shutdown(struct pt_regs *regs)
> {
> + unsigned long msecs;
Int should be enough here? Not that it makes a difference on ARM, but
anyway. :)
> +
> local_irq_disable();
> +
> + atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
> + smp_call_function(machine_crash_nonpanic_core, NULL, false);
> + msecs = 1000; /* Wait at most a second for the other cpus to stop */
> + while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
> + mdelay(1);
> + msecs--;
> + }
If anything, logging here if not all cpus were stopped would be more
useful.
> crash_save_cpu(regs, smp_processor_id());
>
> printk(KERN_INFO "Loading crashdump kernel...\n");
