Re: [PATCH] x86: add show_lapic=

[Cyrill Gorcunov <gorcunov@gmail.com>]

[Yinghai Lu - Sun, Sep 27, 2009 at 01:29:22AM -0700]
| Cyrill Gorcunov wrote:
| > [Yinghai Lu - Sun, Sep 27, 2009 at 12:01:52AM -0700]
| > | 
| > | so could use that together with apci=debug to print less cpu apic.
| > | 
| > | otherwise for system have more cpus will take a while
| > | 
| > | also move apic_verbosity check to print_all_ICs
| > | 
| > | Signed-off-by: Yinghai Lu <yinghai@kernel.org>
| > | 
| > | ---
| > |  arch/x86/kernel/apic/io_apic.c |   42 ++++++++++++++++++++++++++---------------
| > |  1 file changed, 27 insertions(+), 15 deletions(-)
| > ...
| > 
| > Hi Yinghai, good idea!
| > 
| > I've tuned your patch a bit together with changelog.
| > 
| > 1) show_lapic=1 by default does change current kernel behaviour
| >    so it should be set to max cpu available.
| 
| think about system with lots of cpu. but i still want to use apic=debug

but you should not change current behaviour. starting with this change
I'll get only first apic dump, so if I don;t know how many apics I have
what the number I should pass? Does it mean I would need to
pass say show_lapic=2, or 4, or 6 or whatever  _all-the-time_ to be sure
my Core2Duo prints all lapics?

| 
| > 2) show_lapic contains the max number of lapics being printed
| >    so we need to count them instead of plain comparation with
| >    cpu number, as a result I've changed print_local_APICs. Or
| >    you meant _exactly_ cpuid number? In meaning like
| >    show_lapic=max_cpuid. Hmm?
| > 
| your change anything about that. there is not gap between cpu id.

you walk with for_each_online_cpu with is not the same
as for_each_present_cpu. yes, at this stage we hardly get
the situation when cpu initialized and then suddenly get
offline status but anyway

| 
| YH
| 
	-- Cyrill