Commit b2129a39 authored Mar 23, 2026 by Mike Rapoport (Microsoft)

memblock: make free_reserved_area() update memblock if ARCH_KEEP_MEMBLOCK=y

On architectures that keep memblock after boot, freeing of reserved memory
with free_reserved_area() is paired with an update of memblock arrays,
usually by a call to memblock_free().

Make free_reserved_area() directly update memblock.reserved when
ARCH_KEEP_MEMBLOCK is enabled.

Remove the now-redundant explicit memblock_free() call from
arm64::free_initmem() and the #ifdef CONFIG_ARCH_KEEP_MEMBLOCK block
from the generic free_initrd_mem().

Link: https://patch.msgid.link/20260323074836.3653702-8-rppt@kernel.org


Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

parent 7fbc5e26

arch/arm64/mm/init.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -385,9 +385,6 @@ void free_initmem(void)
		WARN_ON(!IS_ALIGNED((unsigned long)lm_init_begin, PAGE_SIZE));
		WARN_ON(!IS_ALIGNED((unsigned long)lm_init_end, PAGE_SIZE));

		/* Delete __init region from memblock.reserved. */
		memblock_free(lm_init_begin, lm_init_end - lm_init_begin);

		free_reserved_area(lm_init_begin, lm_init_end,
		POISON_FREE_INITMEM, "unused kernel");
		/*

init/initramfs.c

+0 −7

Original line number	Diff line number	Diff line
		@@ -652,13 +652,6 @@ void __init reserve_initrd_mem(void)

		void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
		{
		#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
		unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE);
		unsigned long aligned_end = ALIGN(end, PAGE_SIZE);

		memblock_free((void *)aligned_start, aligned_end - aligned_start);
		#endif

		free_reserved_area((void )start, (void )end, POISON_FREE_INITMEM,
		"initrd");
		}

mm/memblock.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -943,6 +943,12 @@ unsigned long free_reserved_area(void start, void end, int poison, const char
		end_pa = __pa(end - 1) + 1;
		}

		if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) {
		if (start_pa < end_pa)
		memblock_remove_range(&memblock.reserved,
		start_pa, end_pa - start_pa);
		}

		pages = __free_reserved_area(start_pa, end_pa, poison);
		if (pages && s)
		pr_info("Freeing %s memory: %ldK\n", s, K(pages));