Subject: Re: [x86-tip] RSDP changes converted i4790 box SMP -> UP
To: Mike Galbraith <mgalbraith@suse.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>
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From: Juergen Gross <jgross@suse.com>
Message-ID: <668caea1-5a34-cf8e-a515-a7fa126bb7ee@suse.com>
Date: Fri, 12 Jan 2018 07:40:17 +0100
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Sender: linux-kernel-owner@vger.kernel.org

On 12/01/18 05:25, Mike Galbraith wrote:
> Hi Juergen,
> 
> Yesterday I wanted to test the RETPOLINE stuff in tip and tip-rt, but
> discovered instead that my box had turned into a complete slug, not due
> to incredible RETPOLINE overhead, rather because box had forgotten that
> it had more than one CPU. ?I was going to leave it for the weekend, but
> firing up gitk over morning java, I noticed the commits below, and sure
> enough, that's what broke my box. ?Given other people's boxen work,
> seems likely that the authors of the AMI BIOS in this box were a bit
> more creative than usual.

So I'm curious how this should be possible.

Some questions:

- which bootloader are you using?
- what does /sys/kernel/boot_params/version contain?
- can you print the returned value of acpi_arch_get_root_pointer()
  in acpi_os_get_root_pointer() with the patches applied and report
  it, please?

Juergen