[PATCH] memblock: make keeping memblock memory opt-in rather than opt-out

From: Mike Rapoport
Date: Wed Apr 24 2019 - 06:36:14 EST


Most architectures do not need the memblock memory after the page allocator
is initialized, but only few enable ARCH_DISCARD_MEMBLOCK in the
arch Kconfig.

Replacing ARCH_DISCARD_MEMBLOCK with ARCH_KEEP_MEMBLOCK and inverting the
logic makes it clear which architectures actually use memblock after system
initialization and skips the necessity to add ARCH_DISCARD_MEMBLOCK to the
architectures that are still missing that option.

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
---
arch/arm/Kconfig | 2 +-
arch/arm64/Kconfig | 1 +
arch/hexagon/Kconfig | 1 -
arch/ia64/Kconfig | 1 -
arch/m68k/Kconfig | 1 -
arch/mips/Kconfig | 1 -
arch/nios2/Kconfig | 1 -
arch/powerpc/Kconfig | 1 +
arch/s390/Kconfig | 1 +
arch/sh/Kconfig | 1 -
arch/x86/Kconfig | 1 -
include/linux/memblock.h | 3 ++-
kernel/kexec_file.c | 16 ++++++++--------
mm/Kconfig | 2 +-
mm/memblock.c | 6 +++---
mm/page_alloc.c | 3 +--
16 files changed, 19 insertions(+), 23 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 850b480..7073436 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -4,7 +4,6 @@ config ARM
default y
select ARCH_32BIT_OFF_T
select ARCH_CLOCKSOURCE_DATA
- select ARCH_DISCARD_MEMBLOCK if !HAVE_ARCH_PFN_VALID && !KEXEC
select ARCH_HAS_DEBUG_VIRTUAL if MMU
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
@@ -21,6 +20,7 @@ config ARM
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_HAS_GCOV_PROFILE_ALL
+ select ARCH_KEEP_MEMBLOCK if HAVE_ARCH_PFN_VALID || KEXEC
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_NO_SG_CHAIN if !ARM_HAS_SG_CHAIN
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7e34b9e..d71f043 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -58,6 +58,7 @@ config ARM64
select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT
select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT
select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT
+ select ARCH_KEEP_MEMBLOCK
select ARCH_USE_CMPXCHG_LOCKREF
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index ac44168..bbe3819 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -22,7 +22,6 @@ config HEXAGON
select GENERIC_IRQ_SHOW
select HAVE_ARCH_KGDB
select HAVE_ARCH_TRACEHOOK
- select ARCH_DISCARD_MEMBLOCK
select NEED_SG_DMA_LENGTH
select NO_IOPORT_MAP
select GENERIC_IOMAP
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 8d7396b..bd51d3b 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -33,7 +33,6 @@ config IA64
select ARCH_HAS_DMA_COHERENT_TO_PFN if SWIOTLB
select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB
select VIRT_TO_BUS
- select ARCH_DISCARD_MEMBLOCK
select GENERIC_IRQ_PROBE
select GENERIC_PENDING_IRQ if SMP
select GENERIC_IRQ_SHOW
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index b542064..7d1e5d9 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -27,7 +27,6 @@ config M68K
select MODULES_USE_ELF_RELA
select OLD_SIGSUSPEND3
select OLD_SIGACTION
- select ARCH_DISCARD_MEMBLOCK

config CPU_BIG_ENDIAN
def_bool y
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 4a5f5b0..8b9298b 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -5,7 +5,6 @@ config MIPS
select ARCH_32BIT_OFF_T if !64BIT
select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
select ARCH_CLOCKSOURCE_DATA
- select ARCH_DISCARD_MEMBLOCK
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UBSAN_SANITIZE_ALL
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 4ef15a6..dc4239c 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -23,7 +23,6 @@ config NIOS2
select SPARSE_IRQ
select USB_ARCH_HAS_HCD if USB_SUPPORT
select CPU_NO_EFFICIENT_FFS
- select ARCH_DISCARD_MEMBLOCK

config GENERIC_CSUM
def_bool y
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 2d0be82..39877b9 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -143,6 +143,7 @@ config PPC
select ARCH_HAS_UBSAN_SANITIZE_ALL
select ARCH_HAS_ZONE_DEVICE if PPC_BOOK3S_64
select ARCH_HAVE_NMI_SAFE_CMPXCHG
+ select ARCH_KEEP_MEMBLOCK
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_MIGHT_HAVE_PC_SERIO
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index b6e3d06..3eaf660 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -106,6 +106,7 @@ config S390
select ARCH_INLINE_WRITE_UNLOCK_BH
select ARCH_INLINE_WRITE_UNLOCK_IRQ
select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
+ select ARCH_KEEP_MEMBLOCK
select ARCH_SAVE_PAGE_KEYS if HIBERNATION
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_NUMA_BALANCING
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index b1c91ea..418e928 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -10,7 +10,6 @@ config SUPERH
select DMA_DECLARE_COHERENT
select HAVE_IDE if HAS_IOPORT_MAP
select HAVE_MEMBLOCK_NODE_MAP
- select ARCH_DISCARD_MEMBLOCK
select HAVE_OPROFILE
select HAVE_ARCH_TRACEHOOK
select HAVE_PERF_EVENTS
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 62fc3fd..80bc582 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -48,7 +48,6 @@ config X86
select ARCH_32BIT_OFF_T if X86_32
select ARCH_CLOCKSOURCE_DATA
select ARCH_CLOCKSOURCE_INIT
- select ARCH_DISCARD_MEMBLOCK
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEVMEM_IS_ALLOWED
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 294d5d8..6ba69ba 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -96,13 +96,14 @@ struct memblock {
extern struct memblock memblock;
extern int memblock_debug;

-#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
+#ifndef CONFIG_ARCH_KEEP_MEMBLOCK
#define __init_memblock __meminit
#define __initdata_memblock __meminitdata
void memblock_discard(void);
#else
#define __init_memblock
#define __initdata_memblock
+static inline void memblock_discard(void) {}
#endif

#define memblock_dbg(fmt, ...) \
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index f1d0e00..623b022 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -500,13 +500,7 @@ static int locate_mem_hole_callback(struct resource *res, void *arg)
return locate_mem_hole_bottom_up(start, end, kbuf);
}

-#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
-static int kexec_walk_memblock(struct kexec_buf *kbuf,
- int (*func)(struct resource *, void *))
-{
- return 0;
-}
-#else
+#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
static int kexec_walk_memblock(struct kexec_buf *kbuf,
int (*func)(struct resource *, void *))
{
@@ -550,6 +544,12 @@ static int kexec_walk_memblock(struct kexec_buf *kbuf,

return ret;
}
+#else
+static int kexec_walk_memblock(struct kexec_buf *kbuf,
+ int (*func)(struct resource *, void *))
+{
+ return 0;
+}
#endif

/**
@@ -589,7 +589,7 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
return 0;

- if (IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK))
+ if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
else
ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
diff --git a/mm/Kconfig b/mm/Kconfig
index 25c71eb..1e1c6ce 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -136,7 +136,7 @@ config HAVE_MEMBLOCK_PHYS_MAP
config HAVE_GENERIC_GUP
bool

-config ARCH_DISCARD_MEMBLOCK
+config ARCH_KEEP_MEMBLOCK
bool

config MEMORY_ISOLATION
diff --git a/mm/memblock.c b/mm/memblock.c
index e7665cf..d6b5755 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -94,7 +94,7 @@
* :c:func:`mem_init` function frees all the memory to the buddy page
* allocator.
*
- * If an architecure enables %CONFIG_ARCH_DISCARD_MEMBLOCK, the
+ * Unless an architecure enables %CONFIG_ARCH_KEEP_MEMBLOCK, the
* memblock data structures will be discarded after the system
* initialization compltes.
*/
@@ -375,7 +375,7 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u
}
}

-#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
+#ifndef CONFIG_ARCH_KEEP_MEMBLOCK
/**
* memblock_discard - discard memory and reserved arrays if they were allocated
*/
@@ -1923,7 +1923,7 @@ unsigned long __init memblock_free_all(void)
return pages;
}

-#if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK)
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_ARCH_KEEP_MEMBLOCK)

static int memblock_debug_show(struct seq_file *m, void *private)
{
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c6ce20a..a1825e9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1831,10 +1831,9 @@ void __init page_alloc_init_late(void)
/* Reinit limits that are based on free pages after the kernel is up */
files_maxfiles_init();
#endif
-#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
+
/* Discard memblock private memory */
memblock_discard();
-#endif

for_each_populated_zone(zone)
set_zone_contiguous(zone);
--
2.7.4