[PATCH 0/4] x86/mm: replace GFP_ATOMIC with GFP_KERNEL for direct map allocations

[Mike Rapoport]

From: Mike Rapoport <rppt@xxxxxxxxxxxxx>

Hi,

The direct map pages on x86 that are allocated using alloc_low_pages() and
spp_getpage() functions. When these functions take 'after_bootmem' branch,
the memory is allocated from buddy with GFP_ATOMIC and I could not find any
reason for this.

Since most of the kernel page tables are anyway allocated really early,
only GART IOMMU initialization and memory hotplug would actually use
get_free_pages() to allocate direct map entries and neither of them happen
in an atomic context, so it would be fine to use GFP_KERNEL. This will give
the page allocator more flexibility when memory hotplug creates the direct
map for hot-added memory and won't use precious atomic memory resources.

The first three patches are trivial cleanups I've encountered while
analysing call paths of alloc_low_pages() and spp_getpage() and the fourth
patch actually replaces GFP_ATOMIC with GFP_KERNEL in those functions.

Mike Rapoport (4):
  x86/mm: make init_trampoline_kaslr() __init
  x86/mm: make kernel_physical_mapping_change() __init
  x86/mm: init_64: make set_pte_vaddr_p4d static
  x86/mm: replace GFP_ATOMIC with GFP_KERNEL for direct map allocations

 arch/x86/include/asm/pgtable_64.h | 1 -
 arch/x86/mm/init.c                | 2 +-
 arch/x86/mm/init_64.c             | 7 ++++---
 arch/x86/mm/kaslr.c               | 2 +-
 4 files changed, 6 insertions(+), 6 deletions(-)


base-commit: d2f38a3c6507b2520101f9a3807ed98f1bdc545a
-- 
2.28.0