Re: [PATCH V3 (RESEND) 0/3] arm64: Enable vmemmap mapping from device memory

[Mike Rapoport]

On Thu, Jun 18, 2020 at 06:45:27AM +0530, Anshuman Khandual wrote:
> This series enables vmemmap backing memory allocation from device memory
> ranges on arm64. But before that, it enables vmemmap_populate_basepages()
> and vmemmap_alloc_block_buf() to accommodate struct vmem_altmap based
> alocation requests.
> 
> This series applies on 5.8-rc1.
> 
> Pending Question:
> 
> altmap_alloc_block_buf() does not have any other remaining users in
> the tree after this change. Should it be converted into a static
> function and it's declaration be dropped from the header
> (include/linux/mm.h). Avoided doing so because I was not sure if there
> are any off-tree users or not.

Well, off-tree users probably have an active fork anyway so they could
switch to vmemmap_alloc_block_buf()...

Regardless, can you please update Documentation/vm/memory-model.rst to
keep it in sync with the code?

> Changes in V3:
> 
> - Dropped comment from free_hotplug_page_range() per Robin
> - Modified comment in unmap_hotplug_range() per Robin
> - Enabled altmap support in vmemmap_alloc_block_buf() per Robin
> 
> Changes in V2: (https://lkml.org/lkml/2020/3/4/475)
> 
> - Rebased on latest hot-remove series (v14) adding P4D page table support
> 
> Changes in V1: (https://lkml.org/lkml/2020/1/23/12)
> 
> - Added an WARN_ON() in unmap_hotplug_range() when altmap is
>   provided without the page table backing memory being freed
> 
> Changes in RFC V2: (https://lkml.org/lkml/2019/10/21/11)
> 
> - Changed the commit message on 1/2 patch per Will
> - Changed the commit message on 2/2 patch as well
> - Rebased on arm64 memory hot remove series (v10)
> 
> RFC V1: (https://lkml.org/lkml/2019/6/28/32)
> 
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> Cc: Tony Luck <tony.luck@xxxxxxxxx>
> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Cc: Andy Lutomirski <luto@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-ia64@xxxxxxxxxxxxxxx
> Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
> Cc: x86@xxxxxxxxxx
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> 
> Anshuman Khandual (3):
>   mm/sparsemem: Enable vmem_altmap support in vmemmap_populate_basepages()
>   mm/sparsemem: Enable vmem_altmap support in vmemmap_alloc_block_buf()
>   arm64/mm: Enable vmem_altmap support for vmemmap mappings
> 
>  arch/arm64/mm/mmu.c       | 59 ++++++++++++++++++++++++++-------------
>  arch/ia64/mm/discontig.c  |  2 +-
>  arch/powerpc/mm/init_64.c | 10 +++----
>  arch/riscv/mm/init.c      |  2 +-
>  arch/x86/mm/init_64.c     | 12 ++++----
>  include/linux/mm.h        |  8 ++++--
>  mm/sparse-vmemmap.c       | 38 ++++++++++++++++++++-----
>  7 files changed, 87 insertions(+), 44 deletions(-)
> 
> -- 
> 2.20.1
> 

-- 
Sincerely yours,
Mike.