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

From	Russell King - ARM Linux <linux@arm.linux.org.uk>
Newsgroups	linux.kernel
Subject	Re: [PATCH] ARM: socfpga: add smp_ops.cpu_kill to make kexec/kdump available
Date	2015-06-03 02:00 +0200
Message-ID	<px4g9-8sG-3@gated-at.bofh.it> (permalink)
References	<pvlEt-31A-9@gated-at.bofh.it> <pvnZD-6qE-5@gated-at.bofh.it> <pwPTQ-46C-27@gated-at.bofh.it> <pwPTQ-46C-25@gated-at.bofh.it> <px46t-8h0-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Wed, Jun 03, 2015 at 08:40:51AM +0900, Hiraku Toyooka wrote:
> 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)

Please put a comment in your hotplug code describing this, so I'm
not likely to ask again (and I don't have to remember that I've
asked the question.)  Thanks.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Re: [PATCH] ARM: socfpga: add smp_ops.cpu_kill to make kexec/kdump  available Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> - 2015-06-03 01:50 +0200
  Re: [PATCH] ARM: socfpga: add smp_ops.cpu_kill to make kexec/kdump  available Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-06-03 02:00 +0200

csiph-web