Commit 6faea342 authored by Mike Rapoport (Microsoft)'s avatar Mike Rapoport (Microsoft) Committed by Andrew Morton
Browse files

arch, mm: streamline HIGHMEM freeing 

All architectures that support HIGHMEM have their code that frees high
memory pages to the buddy allocator while __free_memory_core() is limited
to freeing only low memory.

There is no actual reason for that.  The memory map is completely ready by
the time memblock_free_all() is called and high pages can be released to
the buddy allocator along with low memory.

Remove low memory limit from __free_memory_core() and drop per-architecture
code that frees high memory pages.

Link: https://lkml.kernel.org/r/20250313135003.836600-12-rppt@kernel.org


Signed-off-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>	[x86]
Tested-by: default avatarMark Brown <broonie@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Guo Ren (csky) <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e120d1bc

arch/arc/mm/init.c

+1 −5
Original line number Diff line number Diff line
@@ -160,11 +160,7 @@ void __init setup_arch_memory(void) 
static void __init highmem_init(void)

{

#ifdef CONFIG_HIGHMEM

	unsigned long tmp;



	memblock_phys_free(high_mem_start, high_mem_sz);

	for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)

		free_highmem_page(pfn_to_page(tmp));

#endif

}
@@ -176,8 +172,8 @@ static void __init highmem_init(void) 
 */

void __init mem_init(void)

{

	memblock_free_all();

	highmem_init();

	memblock_free_all();



	BUILD_BUG_ON((PTRS_PER_PGD * sizeof(pgd_t)) > PAGE_SIZE);

	BUILD_BUG_ON((PTRS_PER_PUD * sizeof(pud_t)) > PAGE_SIZE);

arch/arm/mm/init.c

+0 −29
Original line number Diff line number Diff line
@@ -237,33 +237,6 @@ static inline void poison_init_mem(void *s, size_t count) 
		*p++ = 0xe7fddef0;

}



static void __init free_highpages(void)

{

#ifdef CONFIG_HIGHMEM

	unsigned long max_low = max_low_pfn;

	phys_addr_t range_start, range_end;

	u64 i;



	/* set highmem page free */

	for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,

				&range_start, &range_end, NULL) {

		unsigned long start = PFN_UP(range_start);

		unsigned long end = PFN_DOWN(range_end);



		/* Ignore complete lowmem entries */

		if (end <= max_low)

			continue;



		/* Truncate partial highmem entries */

		if (start < max_low)

			start = max_low;



		for (; start < end; start++)

			free_highmem_page(pfn_to_page(start));

	}

#endif

}



/*

 * mem_init() marks the free areas in the mem_map and tells us how much

 * memory is free.  This is done after various parts of the system have
@@ -283,8 +256,6 @@ void __init mem_init(void) 
	/* this will put all unused low memory onto the freelists */

	memblock_free_all();



	free_highpages();



	/*

	 * Check boundaries twice: Some fundamental inconsistencies can

	 * be detected at build time already.

arch/csky/mm/init.c

+0 −14
Original line number Diff line number Diff line
@@ -44,21 +44,7 @@ EXPORT_SYMBOL(empty_zero_page); 


void __init mem_init(void)

{

#ifdef CONFIG_HIGHMEM

	unsigned long tmp;

#endif



	memblock_free_all();



#ifdef CONFIG_HIGHMEM

	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {

		struct page *page = pfn_to_page(tmp);



		/* FIXME not sure about */

		if (!memblock_is_reserved(tmp << PAGE_SHIFT))

			free_highmem_page(page);

	}

#endif

}



void free_initmem(void)

arch/microblaze/mm/init.c

+0 −16
Original line number Diff line number Diff line
@@ -52,19 +52,6 @@ static void __init highmem_init(void) 
	map_page(PKMAP_BASE, 0, 0);	/* XXX gross */

	pkmap_page_table = virt_to_kpte(PKMAP_BASE);

}



static void __meminit highmem_setup(void)

{

	unsigned long pfn;



	for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {

		struct page *page = pfn_to_page(pfn);



		/* FIXME not sure about */

		if (!memblock_is_reserved(pfn << PAGE_SHIFT))

			free_highmem_page(page);

	}

}

#endif /* CONFIG_HIGHMEM */



/*
@@ -122,9 +109,6 @@ void __init mem_init(void) 
{

	/* this will put all memory onto the freelists */

	memblock_free_all();

#ifdef CONFIG_HIGHMEM

	highmem_setup();

#endif



	mem_init_done = 1;

}

arch/mips/mm/init.c

+0 −20
Original line number Diff line number Diff line
@@ -425,25 +425,6 @@ void __init paging_init(void) 
static struct kcore_list kcore_kseg0;

#endif



static inline void __init mem_init_free_highmem(void)

{

#ifdef CONFIG_HIGHMEM

	unsigned long tmp;



	if (cpu_has_dc_aliases)

		return;



	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {

		struct page *page = pfn_to_page(tmp);



		if (!memblock_is_memory(PFN_PHYS(tmp)))

			SetPageReserved(page);

		else

			free_highmem_page(page);

	}

#endif

}



void __init mem_init(void)

{

	/*
@@ -454,7 +435,6 @@ void __init mem_init(void) 


	maar_init();

	setup_zero_pages();	/* Setup zeroed pages.  */

	mem_init_free_highmem();

	memblock_free_all();



#ifdef CONFIG_64BIT