[PATCH v7 00/12] kexec kernel efi runtime support

[Dave Young]

On 12/23/13 at 07:36am, Matt Fleming wrote:
> On Sun, 22 Dec, at 02:27:01PM, Toshi Kani wrote:
> > 
> > The kexec branch is missing the following change, which is required for
> > fast reboot with multi-cpus.
> > 
> >    commit 279f1df915c3a6ed3075d98a849705bf53851f99
> >    Author: Vivek Goyal <vgoyal at redhat.com>
> >    Date:   Tue Nov 26 10:25:28 2013 +0800
> > 
> >        kexec: migrate to reboot cpu
> > 
> > With this change added, I confirmed that the branch kernel works fine.
>  
> I can't find that commit in Linus' tree. Where is it from?

Previously it was in Andrew's mm tree, currently it's below commit in linus tree:

commit c97102ba96324da330078ad8619ba4dfe840dbe3
Author: Vivek Goyal <vgoyal at redhat.com>
Date:   Wed Dec 18 17:08:31 2013 -0800

    kexec: migrate to reboot cpu
    
    Commit 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic
    kernel") moved reboot= handling to generic code.  In the process it also
    removed the code in native_machine_shutdown() which are moving reboot
    process to reboot_cpu/cpu0.
    
    I guess that thought must have been that all reboot paths are calling
    migrate_to_reboot_cpu(), so we don't need this special handling.  But
    kexec reboot path (kernel_kexec()) is not calling
    migrate_to_reboot_cpu() so above change broke kexec.  Now reboot can
    happen on non-boot cpu and when INIT is sent in second kerneo to bring
    up BP, it brings down the machine.
    
    So start calling migrate_to_reboot_cpu() in kexec reboot path to avoid
    this problem.
    
    Bisected by WANG Chao.
    
    Reported-by: Matthew Whitehead <mwhitehe at redhat.com>
    Reported-by: Dave Young <dyoung at redhat.com>
    Signed-off-by: Vivek Goyal <vgoyal at redhat.com>
    Tested-by: Baoquan He <bhe at redhat.com>
    Tested-by: WANG Chao <chaowang at redhat.com>
    Acked-by: H. Peter Anvin <hpa at linux.intel.com>
    Cc: <stable at vger.kernel.org>
    Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>