bootmem: Add free_bootmem_late() (9f993ac3) · Commits · 戴 / test

Add a new function for freeing bootmem after the bootmem allocator has been released and the unreserved pages given to the page allocator. This allows us to reserve bootmem and then release it if we later discover it was not needed. ( This new API will be used by the swiotlb code to recover a significant amount of RAM (64MB). ) Signed-off-by:

FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by:

Pekka Enberg <penberg@cs.helsinki.fi> Cc: chrisw@sous-sol.org Cc: dwmw2@infradead.org Cc: joerg.roedel@amd.com Cc: muli@il.ibm.com Cc: hannes@cmpxchg.org Cc: tj@kernel.org Cc: akpm@linux-foundation.org Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <1257849980-22640-7-git-send-email-fujita.tomonori@lab.ntt.co.jp> Signed-off-by:

Ingo Molnar <mingo@elte.hu>

include/linux/bootmem.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -53,6 +53,7 @@ extern void free_bootmem_node(pg_data_t *pgdat,
		unsigned long addr,
		unsigned long size);
		extern void free_bootmem(unsigned long addr, unsigned long size);
		extern void free_bootmem_late(unsigned long addr, unsigned long size);

		/*
		* Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE,

mm/bootmem.c

+24 −0

Original line number	Diff line number	Diff line
		@@ -143,6 +143,30 @@ unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
		return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);
		}

		/*
		* free_bootmem_late - free bootmem pages directly to page allocator
		* @addr: starting address of the range
		* @size: size of the range in bytes
		*
		* This is only useful when the bootmem allocator has already been torn
		* down, but we are still initializing the system. Pages are given directly
		* to the page allocator, no bootmem metadata is updated because it is gone.
		*/
		void __init free_bootmem_late(unsigned long addr, unsigned long size)
		{
		unsigned long cursor, end;

		kmemleak_free_part(__va(addr), size);

		cursor = PFN_UP(addr);
		end = PFN_DOWN(addr + size);

		for (; cursor < end; cursor++) {
		__free_pages_bootmem(pfn_to_page(cursor), 0);
		totalram_pages++;
		}
		}

		static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
		{
		int aligned;

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