Re: [PATCH v5 0/8] huge vmalloc mappings

From: Christophe Leroy
Date: Fri Aug 21 2020 - 01:48:12 EST




Le 21/08/2020 à 06:44, Nicholas Piggin a écrit :
I made this powerpc-only for the time being. It shouldn't be too hard to
add support for other archs that define HUGE_VMAP. I have booted x86
with it enabled, just may not have audited everything.

I like this series, but if I understand correctly it enables huge vmalloc mappings only for hugepages sizes matching a page directory levels, ie on a PPC32 it would work only for 4M hugepages.

On the 8xx, we only have 8M and 512k hugepages. Any change that it can support these as well one day ?

Christophe


Hi Andrew, would you care to put this in your tree?

Thanks,
Nick

Since v4:
- Fixed an off-by-page-order bug in v4
- Several minor cleanups.
- Added page order to /proc/vmallocinfo
- Added hugepage to alloc_large_system_hage output.
- Made an architecture config option, powerpc only for now.

Since v3:
- Fixed an off-by-one bug in a loop
- Fix !CONFIG_HAVE_ARCH_HUGE_VMAP build fail
- Hopefully this time fix the arm64 vmap stack bug, thanks Jonathan
Cameron for debugging the cause of this (hopefully).

Since v2:
- Rebased on vmalloc cleanups, split series into simpler pieces.
- Fixed several compile errors and warnings
- Keep the page array and accounting in small page units because
struct vm_struct is an interface (this should fix x86 vmap stack debug
assert). [Thanks Zefan]

Nicholas Piggin (8):
mm/vmalloc: fix vmalloc_to_page for huge vmap mappings
mm: apply_to_pte_range warn and fail if a large pte is encountered
mm/vmalloc: rename vmap_*_range vmap_pages_*_range
lib/ioremap: rename ioremap_*_range to vmap_*_range
mm: HUGE_VMAP arch support cleanup
mm: Move vmap_range from lib/ioremap.c to mm/vmalloc.c
mm/vmalloc: add vmap_range_noflush variant
mm/vmalloc: Hugepage vmalloc mappings

.../admin-guide/kernel-parameters.txt | 2 +
arch/Kconfig | 4 +
arch/arm64/mm/mmu.c | 12 +-
arch/powerpc/Kconfig | 1 +
arch/powerpc/mm/book3s64/radix_pgtable.c | 10 +-
arch/x86/mm/ioremap.c | 12 +-
include/linux/io.h | 9 -
include/linux/vmalloc.h | 13 +
init/main.c | 1 -
mm/ioremap.c | 231 +--------
mm/memory.c | 60 ++-
mm/page_alloc.c | 4 +-
mm/vmalloc.c | 456 +++++++++++++++---
13 files changed, 476 insertions(+), 339 deletions(-)