Hi

On 2020/3/31 13:09, 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.

I verified no obvious regression after this patch series.

Host: ThunderX2(armv8a server), kernel v5.4

qemu:v3.1, -M virt \

-object 
memory-backend-file,id=mem1,share=on,mem-path=/tmp2/nvdimm.img,size=4G,align=2M \

-device nvdimm,id=nvdimm1,memdev=mem1,label-size=2M

Guest: kernel v5.7.0-rc5 with this patch series.

Tested case:

- 4K PAGESIZE, boot, mount w/ -o dax, mount w/o -o dax, basic io

- 64K PAGESIZE,boot, mount w/ -o dax, mount w/o -o dax, basic io

Not tested:

- 16K pagesize due to my hardware limiation(can't run 16K pgsz kernel)

- hot-add/remove nvdimm device from qemu due to no fully support on arm64 qemu yet

- Host nvdimm device hotplug

Hence from above result,

Tested-by: Jia He <redacted>

This series applies after latest (v14) arm64 memory hot remove series
(https://lkml.org/lkml/2020/3/3/1746) on Linux 5.6.

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.

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@arm.com>
Cc: Will Deacon<will@kernel.org>
Cc: Mark Rutland<mark.rutland@arm.com>
Cc: Paul Walmsley<redacted>
Cc: Palmer Dabbelt<palmer@dabbelt.com>
Cc: Tony Luck<tony.luck@intel.com>
Cc: Fenghua Yu<redacted>
Cc: Dave Hansen<dave.hansen@linux.intel.com>
Cc: Andy Lutomirski<luto@kernel.org>
Cc: Peter Zijlstra<peterz@infradead.org>
Cc: Thomas Gleixner<redacted>
Cc: Ingo Molnar<mingo@redhat.com>
Cc: David Hildenbrand<redacted>
Cc: Mike Rapoport<redacted>
Cc: Michal Hocko<mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)"<willy@infradead.org>
Cc: "Kirill A. Shutemov"<redacted>
Cc: Andrew Morton<akpm@linux-foundation.org>
Cc: Dan Williams<redacted>
Cc: Pavel Tatashin<pasha.tatashin@soleen.com>
Cc: Benjamin Herrenschmidt<benh@kernel.crashing.org>
Cc: Paul Mackerras<redacted>
Cc: Michael Ellerman<mpe@ellerman.id.au>
Cc:linux-arm-kernel@lists.infradead.org
Cc:linux-ia64@vger.kernel.org
Cc:linux-riscv@lists.infradead.org
Cc:x86@kernel.org
Cc:linuxppc-dev@lists.ozlabs.org
Cc:linux-mm@kvack.org
Cc:linux-kernel@vger.kernel.org

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(-)

-- 

---
Cheers,
Justin (Jia He)