LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Ingo Molnar <mingo@elte.hu>
To: Ivan Vecera <ivecera@redhat.com>
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de,
	mingo@redhat.com, hpa@zytor.com, nhorman@redhat.com,
	jmarchan@redhat.com
Subject: Re: [PATCH] x86: call machine_shutdown and stop all CPUs in native_machine_halt
Date: Mon, 20 Oct 2008 18:00:58 +0200	[thread overview]
Message-ID: <20081020160058.GB22779@elte.hu> (raw)
In-Reply-To: <1224504787-11403-1-git-send-email-ivecera@redhat.com>


* Ivan Vecera <ivecera@redhat.com> wrote:

> Function machine_halt (resp. native_machine_halt) is empty for x86 
> architectures. When command 'halt -f' is invoked, the message "System 
> halted." is displayed but this is not really true because all CPUs are 
> still running. There are also similar inconsistencies for other arches 
> (some uses power-off for halt or forever-loop with IRQs 
> enabled/disabled). IMO there should be used the same approach for all 
> architectures OR what does the message "System halted" really mean?

no fundamental objections, but could you please do it a bit cleaner:

>  static void native_machine_halt(void)
>  {
> +	/* stop other cpus and apics */
> +	machine_shutdown();
> +
> +	/* stop this cpu */
> +	local_irq_disable();
> +	if (hlt_works(smp_processor_id()))
> +		for (;;) halt();
> +	for (;;);
>  }

the code in arch/x86/kernel/smp.c::stop_this_cpu() is very similar to 
this and could be shared. You could move the stop_this_cpu() function to 
arch/x86/kernel/process.c (out of smp.c), so that it can be used by 
reboot.c.

furthermore, native_machine_power_off() should probably fall back to 
native_machine_halt() as well - should pm_power_off() be disabled (or if 
it fails to stop the machine).

hm?

	Ingo

  parent reply	other threads:[~2008-10-20 16:01 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-20 12:13 Ivan Vecera
2008-10-20 14:39 ` Neil Horman
2008-10-20 16:00 ` Ingo Molnar [this message]
2008-10-21 12:36   ` Ivan Vecera
2008-11-06 16:10     ` Ivan Vecera
2008-11-06 16:15       ` Neil Horman
2008-11-10 22:49       ` Pavel Machek
2008-11-11 12:48         ` Ivan Vecera
2008-11-06 20:43     ` Ingo Molnar
2008-11-11 12:47       ` Ivan Vecera
2008-11-11 13:47         ` Ingo Molnar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20081020160058.GB22779@elte.hu \
    --to=mingo@elte.hu \
    --cc=hpa@zytor.com \
    --cc=ivecera@redhat.com \
    --cc=jmarchan@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=nhorman@redhat.com \
    --cc=tglx@linutronix.de \
    --subject='Re: [PATCH] x86: call machine_shutdown and stop all CPUs in native_machine_halt' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).