huge vmalloc mappings is supported on PPC[1], but this feature should be not only used on PPC, it could be used on arch support HAVE_ARCH_HUGE_VMAP and PMD sized vmap mappings. this patchset is to enable this feature on arm64/x86. The first patch is to let user to control huge vmalloc mapping default behavior and then enable this feature on arm64/x86. The PPC is enabled by default(it selects HUGE_VMALLOC_DEFAULT_ENABLED), but arm64/x86 should use hugevmalloc=on to enable this feature. NOTE: 1) nohugevmalloc parameter is still supported, the first patch is in case of archs don't want to this feature enabled by default. 2) if people don't like this, we could drop the first patch. [1] https://lore.kernel.org/linux-mm/20210317062402.533919-1-npiggin@xxxxxxxxx/ Kefeng Wang (3): mm: vmalloc: Let user to control huge vmalloc default behavior arm64: Support huge vmalloc mappings x86: Support huge vmalloc mappings .../admin-guide/kernel-parameters.txt | 14 +++++++++++++- arch/arm64/Kconfig | 1 + arch/powerpc/Kconfig | 1 + arch/x86/Kconfig | 1 + mm/Kconfig | 7 +++++++ mm/vmalloc.c | 18 +++++++++++++++++- 6 files changed, 40 insertions(+), 2 deletions(-) -- 2.26.2