diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2021-04-29 22:58:49 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-04-30 11:20:40 -0700 |
| commit | 121e6f3258fe393e22c36f61a319be8a4f2c05ae (patch) | |
| tree | 0e4b1115e5964be35140a54e60d625f6a25d26c6 /arch | |
| parent | 5d87510de15f31d1b26cffced7bc4d504539a2c7 (diff) | |
mm/vmalloc: hugepage vmalloc mappings
Support huge page vmalloc mappings. Config option HAVE_ARCH_HUGE_VMALLOC
enables support on architectures that define HAVE_ARCH_HUGE_VMAP and
supports PMD sized vmap mappings.
vmalloc will attempt to allocate PMD-sized pages if allocating PMD size or
larger, and fall back to small pages if that was unsuccessful.
Architectures must ensure that any arch specific vmalloc allocations that
require PAGE_SIZE mappings (e.g., module allocations vs strict module rwx)
use the VM_NOHUGE flag to inhibit larger mappings.
This can result in more internal fragmentation and memory overhead for a
given allocation, an option nohugevmalloc is added to disable at boot.
[colin.king@canonical.com: fix read of uninitialized pointer area]
Link: https://lkml.kernel.org/r/20210318155955.18220-1-colin.king@canonical.com
Link: https://lkml.kernel.org/r/20210317062402.533919-14-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/Kconfig | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 5e8f6680d4bf..bf27159be4d9 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -829,6 +829,17 @@ config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD config HAVE_ARCH_HUGE_VMAP bool +# +# Archs that select this would be capable of PMD-sized vmaps (i.e., +# arch_vmap_pmd_supported() returns true), and they must make no assumptions +# that vmalloc memory is mapped with PAGE_SIZE ptes. The VM_NO_HUGE_VMAP flag +# can be used to prohibit arch-specific allocations from using hugepages to +# help with this (e.g., modules may require it). +# +config HAVE_ARCH_HUGE_VMALLOC + depends on HAVE_ARCH_HUGE_VMAP + bool + config ARCH_WANT_HUGE_PMD_SHARE bool |