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 | |
| parent | 30a0b95b1335e12efef89dd78518ed3e4a71a763 (diff) | |
| download | linux-b0284cd29a957e62d60c2886fd663be93c56f9c0.tar.bz2 | |
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
| -rw-r--r-- | arch/arm64/Kconfig | 1 | ||||
| -rw-r--r-- | fs/proc/page.c | 2 | ||||
| -rw-r--r-- | include/linux/page-flags.h | 2 | ||||
| -rw-r--r-- | include/trace/events/mmflags.h | 8 | ||||
| -rw-r--r-- | mm/Kconfig | 8 | ||||
| -rw-r--r-- | mm/huge_memory.c | 2 |
6 files changed, 16 insertions, 7 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 505c8a1ccbe0..cd93d0738425 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1965,6 +1965,7 @@ config ARM64_MTE depends on ARM64_PAN select ARCH_HAS_SUBPAGE_FAULTS select ARCH_USES_HIGH_VMA_FLAGS + select ARCH_USES_PG_ARCH_X help Memory Tagging (part of the ARMv8.5 Extensions) provides architectural support for run-time, always-on detection of diff --git a/fs/proc/page.c b/fs/proc/page.c index f2273b164535..882525c8e94c 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -219,7 +219,7 @@ u64 stable_page_flags(struct page *page) u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2); u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1); u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1); -#ifdef CONFIG_64BIT +#ifdef CONFIG_ARCH_USES_PG_ARCH_X u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2); #endif diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 0b0ae5084e60..5dc7977edf9d 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -132,7 +132,7 @@ enum pageflags { PG_young, PG_idle, #endif -#ifdef CONFIG_64BIT +#ifdef CONFIG_ARCH_USES_PG_ARCH_X PG_arch_2, #endif #ifdef CONFIG_KASAN_HW_TAGS diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h index e87cb2b80ed3..d9f6d35fb150 100644 --- a/include/trace/events/mmflags.h +++ b/include/trace/events/mmflags.h @@ -91,10 +91,10 @@ #define IF_HAVE_PG_IDLE(flag,string) #endif -#ifdef CONFIG_64BIT -#define IF_HAVE_PG_ARCH_2(flag,string) ,{1UL << flag, string} +#ifdef CONFIG_ARCH_USES_PG_ARCH_X +#define IF_HAVE_PG_ARCH_X(flag,string) ,{1UL << flag, string} #else -#define IF_HAVE_PG_ARCH_2(flag,string) +#define IF_HAVE_PG_ARCH_X(flag,string) #endif #ifdef CONFIG_KASAN_HW_TAGS @@ -130,7 +130,7 @@ IF_HAVE_PG_UNCACHED(PG_uncached, "uncached" ) \ IF_HAVE_PG_HWPOISON(PG_hwpoison, "hwpoison" ) \ IF_HAVE_PG_IDLE(PG_young, "young" ) \ IF_HAVE_PG_IDLE(PG_idle, "idle" ) \ -IF_HAVE_PG_ARCH_2(PG_arch_2, "arch_2" ) \ +IF_HAVE_PG_ARCH_X(PG_arch_2, "arch_2" ) \ IF_HAVE_PG_SKIP_KASAN_POISON(PG_skip_kasan_poison, "skip_kasan_poison") #define show_page_flags(flags) \ 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 diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 561a42567477..76e7b973919c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2444,7 +2444,7 @@ static void __split_huge_page_tail(struct page *head, int tail, (1L << PG_workingset) | (1L << PG_locked) | (1L << PG_unevictable) | -#ifdef CONFIG_64BIT +#ifdef CONFIG_ARCH_USES_PG_ARCH_X (1L << PG_arch_2) | #endif (1L << PG_dirty) | |