diff options
| author | Catalin Marinas <catalin.marinas@arm.com> | 2022-11-03 18:10:34 -0700 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-11-29 09:26:06 +0000 |
| commit | b0284cd29a957e62d60c2886fd663be93c56f9c0 (patch) | |
| tree | 2b17fdf221c44da29cbc1951a9f46be1f1cafa8f /mm/Kconfig | |
| parent | 30a0b95b1335e12efef89dd78518ed3e4a71a763 (diff) | |
mm: Do not enable PG_arch_2 for all 64-bit architectures
Commit 4beba9486abd ("mm: Add PG_arch_2 page flag") introduced a new
page flag for all 64-bit architectures. However, even if an architecture
is 64-bit, it may still have limited spare bits in the 'flags' member of
'struct page'. This may happen if an architecture enables SPARSEMEM
without SPARSEMEM_VMEMMAP as is the case with the newly added loongarch.
This architecture port needs 19 more bits for the sparsemem section
information and, while it is currently fine with PG_arch_2, adding any
more PG_arch_* flags will trigger build-time warnings.
Add a new CONFIG_ARCH_USES_PG_ARCH_X option which can be selected by
architectures that need more PG_arch_* flags beyond PG_arch_1. Select it
on arm64.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[pcc@google.com: fix build with CONFIG_ARM64_MTE disabled]
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Price <steven.price@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221104011041.290951-2-pcc@google.com
Diffstat (limited to 'mm/Kconfig')
| -rw-r--r-- | mm/Kconfig | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/Kconfig b/mm/Kconfig index 57e1d8c5b505..807bd7192f51 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1005,6 +1005,14 @@ config ARCH_USES_HIGH_VMA_FLAGS config ARCH_HAS_PKEYS bool +config ARCH_USES_PG_ARCH_X + bool + help + Enable the definition of PG_arch_x page flags with x > 1. Only + suitable for 64-bit architectures with CONFIG_FLATMEM or + CONFIG_SPARSEMEM_VMEMMAP enabled, otherwise there may not be + enough room for additional bits in page->flags. + config VM_EVENT_COUNTERS default y bool "Enable VM event counters for /proc/vmstat" if EXPERT |