mm/sparsemem: fix a bug in free_map_bootmem when CONFIG_SPARSEMEM_VMEMMAP (81556b02) · Commits · 戴 / test

We pass the number of pages which hold page structs of a memory section to free_map_bootmem(). This is right when !CONFIG_SPARSEMEM_VMEMMAP but wrong when CONFIG_SPARSEMEM_VMEMMAP. When CONFIG_SPARSEMEM_VMEMMAP, we should pass the number of pages of a memory section to free_map_bootmem. So the fix is removing the nr_pages parameter. When CONFIG_SPARSEMEM_VMEMMAP, we directly use the prefined marco PAGES_PER_SECTION in free_map_bootmem. When !CONFIG_SPARSEMEM_VMEMMAP, we calculate page numbers needed to hold the page structs for a memory section and use the value in free_map_bootmem(). This was found by reading the code. And I have no machine that support memory hot-remove to test the bug now. Signed-off-by:

Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Reviewed-by:

Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/sparse.c

+9 −11

Original line number	Diff line number	Diff line
		@@ -603,10 +603,10 @@ static void __kfree_section_memmap(struct page *memmap)
		vmemmap_free(start, end);
		}
		#ifdef CONFIG_MEMORY_HOTREMOVE
		static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
		static void free_map_bootmem(struct page *memmap)
		{
		unsigned long start = (unsigned long)memmap;
		unsigned long end = (unsigned long)(memmap + nr_pages);
		unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);

		vmemmap_free(start, end);
		}
		@@ -648,12 +648,15 @@ static void __kfree_section_memmap(struct page *memmap)
		}

		#ifdef CONFIG_MEMORY_HOTREMOVE
		static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
		static void free_map_bootmem(struct page *memmap)
		{
		unsigned long maps_section_nr, removing_section_nr, i;
		unsigned long magic;
		unsigned long magic, nr_pages;
		struct page *page = virt_to_page(memmap);

		nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
		>> PAGE_SHIFT;

		for (i = 0; i < nr_pages; i++, page++) {
		magic = (unsigned long) page->lru.next;

		@@ -756,7 +759,6 @@ static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
		static void free_section_usemap(struct page memmap, unsigned long usemap)
		{
		struct page *usemap_page;
		unsigned long nr_pages;

		if (!usemap)
		return;
		@@ -777,12 +779,8 @@ static void free_section_usemap(struct page memmap, unsigned long usemap)
		* on the section which has pgdat at boot time. Just keep it as is now.
		*/

		if (memmap) {
		nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
		>> PAGE_SHIFT;

		free_map_bootmem(memmap, nr_pages);
		}
		if (memmap)
		free_map_bootmem(memmap);
		}

		void sparse_remove_one_section(struct zone zone, struct mem_section ms)

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