Re: [External] [PATCH v2 0/5] x86-64: Remove global variables from boot

[David Woodhouse]

On 24 February 2023 21:38:41 GMT, Brian Gerst <brgerst@xxxxxxxxx> wrote:
>On Fri, Feb 24, 2023 at 3:40 PM Usama Arif <usama.arif@xxxxxxxxxxxxx> wrote:
>>
>>
>>
>> On 24/02/2023 15:42, Brian Gerst wrote:
>> > This is based on the parallel boot v11 series.
>> >
>> > Remove the global variables initial_gs, initial_stack, and
>> > early_gdt_descr from the 64-bit boot code.  The stack, GDT, and GSBASE
>> > can be determined from the CPU number.
>> >
>> > v2: - Dropped first two patches which were merged into another patch in
>> >        the parallel boot series.
>> >      - Fixed a compile error in patch 1 found by the kernel test robot.
>> >      - Split out the removal of STARTUP_SECONDARY into a separate patch
>> >        and renumber the remaining flags.
>> >
>> > Brian Gerst (5):
>> >    x86/smpboot: Remove initial_stack on 64-bit
>> >    x86/smpboot: Remove early_gdt_descr on 64-bit
>> >    x86/smpboot: Remove initial_gs
>> >    x86/smpboot: Simplify boot CPU setup
>> >    x86/smpboot: Remove STARTUP_SECONDARY
>> >
>> >   arch/x86/include/asm/processor.h |  6 +-
>> >   arch/x86/include/asm/realmode.h  |  1 -
>> >   arch/x86/include/asm/smp.h       |  5 +-
>> >   arch/x86/kernel/acpi/sleep.c     |  5 +-
>> >   arch/x86/kernel/head_64.S        | 99 ++++++++++++--------------------
>> >   arch/x86/kernel/smpboot.c        |  6 +-
>> >   arch/x86/xen/xen-head.S          |  2 +-
>> >   7 files changed, 49 insertions(+), 75 deletions(-)
>> >
>>
>> Its weird putting something in earlier patches like
>> STARTUP_APICID_CPUID_*,STARTUP_SECONDARY.. and removing/changing it
>> later on in *the same series*. Maybe better to keep this as a separate
>> series from parallel smp? i.e. not include this in v12 and review it
>> separately? Happy with whatever you and David decide..
>>
>> Thanks,
>> Usama
>
>Removing the globals before the parallel boot series, would be the
>best option IMO.  That would make the transition simpler.

Yeah, makes sense.. Let's do that.