Re: [PATCH v2 1/2] mm/memblock: expose only miminal interface to add/walk physmem

[David Hildenbrand]

On 01.07.20 17:31, Heiko Carstens wrote:
> On Wed, Jul 01, 2020 at 06:06:43PM +0300, Mike Rapoport wrote:
>> Hi David,
>>
>> On Wed, Jul 01, 2020 at 04:18:29PM +0200, David Hildenbrand wrote:
>>> "physmem" in the memblock allocator is somewhat weird: it's not actually
>>> used for allocation, it's simply information collected during boot, which
>>> describes the unmodified physical memory map at boot time, without any
>>> standby/hotplugged memory. It's only used on s390x and is currently the
>>> only reason s390x keeps using CONFIG_ARCH_KEEP_MEMBLOCK.
>>>
>>> Physmem isn't numa aware and current users don't specify any flags. Let's
>>> hide it from the user, exposing only for_each_physmem(), and simplify. The
>>> interface for physmem is now really minimalistic:
>>> - memblock_physmem_add() to add ranges
>>> - for_each_physmem() / __next_physmem_range() to walk physmem ranges
>>>
>>> Don't place it into an __init section and don't discard it without
>>> CONFIG_ARCH_KEEP_MEMBLOCK. As we're reusing __next_mem_range(), remove
>>> the __meminit notifier to avoid section mismatch warnings once
>>> CONFIG_ARCH_KEEP_MEMBLOCK is no longer used with
>>> CONFIG_HAVE_MEMBLOCK_PHYS_MAP.
>>>
>>> While fixing up the documentation, sneak in some related cleanups. We can
>>> stop setting CONFIG_HAVE_MEMBLOCK_PHYS_MAP for s390x next.
>>
>> As you noted in the previous version it should have been
>> CONFIG_ARCH_KEEP_MEMBLOCK ;-)
>>
>>> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
>>> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
>>> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
>>> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
>>> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>>> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
>>
>> Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
>>
>>> ---
>>>  arch/s390/kernel/crash_dump.c |  6 ++--
>>>  include/linux/memblock.h      | 28 ++++++++++++++---
>>>  mm/memblock.c                 | 57 ++++++++++++++++++-----------------
>>>  3 files changed, 55 insertions(+), 36 deletions(-)
> 
> So I guess this should go via the s390 tree, since the second patch of
> this series can go only upstream if both this patch and a patch which
> is currently only on our features are merged before.
> 
> Any objections?

@Andrew, fine with you if this goes via the s390 tree?

-- 
Thanks,

David / dhildenb