Re: [PATCH] ARM: socfpga: add smp_ops.cpu_kill to make kexec/kdump available

From: Hiraku Toyooka
Date: Tue Jun 02 2015 - 19:41:09 EST


Hello, Russell,

On 2015/06/02 17:38, Russell King - ARM Linux wrote:
> I wasn't thinking of SPIs and PPIs, but SGIs - the IPI interrupts coming
> from the boot CPU.

All tasks in a CPU going offline are migrated to other CPUs(finally
CPU0) and the rq is marked with offline before the CPU entering WFI
loop. So IPI is not sent to the secondary CPU.

> If you have a way to reset CPU0, why are you not using this for hotplug
> when a CPU is hot-unplugged?

I think you mean "way to reset CPU1". If so, the reason is an increase
in power consumption in usual hotplug. This is discussed before between
Alan Tull and you. (https://lkml.org/lkml/2014/9/25/37)

Best regards,
Hiraku Toyooka
--
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/