Commit 170a5a7e authored by Jiang Liu's avatar Jiang Liu Committed by Linus Torvalds
Browse files

mm: make __free_pages_bootmem() only available at boot time 



In order to simpilify management of totalram_pages and
zone->managed_pages, make __free_pages_bootmem() only available at boot
time.  With this change applied, __free_pages_bootmem() will only be
used by bootmem.c and nobootmem.c at boot time, so mark it as __init.
Other callers of __free_pages_bootmem() have been converted to use
free_reserved_page(), which handles totalram_pages and
zone->managed_pages in a safer way.

This patch also fix a bug in free_pagetable() for x86_64, which should
increase zone->managed_pages instead of zone->present_pages when freeing
reserved pages.

And now we have managed_pages_count_lock to protect totalram_pages and
zone->managed_pages, so remove the redundant ppb_lock lock in
put_page_bootmem().  This greatly simplifies the locking rules.

Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c3d5f5f0

arch/x86/mm/init_64.c

+2 −16
Original line number Diff line number Diff line
@@ -712,36 +712,22 @@ EXPORT_SYMBOL_GPL(arch_add_memory); 


static void __meminit free_pagetable(struct page *page, int order)

{

	struct zone *zone;

	bool bootmem = false;

	unsigned long magic;

	unsigned int nr_pages = 1 << order;



	/* bootmem page has reserved flag */

	if (PageReserved(page)) {

		__ClearPageReserved(page);

		bootmem = true;



		magic = (unsigned long)page->lru.next;

		if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {

			while (nr_pages--)

				put_page_bootmem(page++);

		} else

			__free_pages_bootmem(page, order);

			while (nr_pages--)

				free_reserved_page(page++);

	} else

		free_pages((unsigned long)page_address(page), order);



	/*

	 * SECTION_INFO pages and MIX_SECTION_INFO pages

	 * are all allocated by bootmem.

	 */

	if (bootmem) {

		zone = page_zone(page);

		zone_span_writelock(zone);

		zone->present_pages += nr_pages;

		zone_span_writeunlock(zone);

		totalram_pages += nr_pages;

	}

}



static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd)

mm/memory_hotplug.c

+2 −14
Original line number Diff line number Diff line
@@ -101,12 +101,9 @@ void get_page_bootmem(unsigned long info, struct page *page, 
	atomic_inc(&page->_count);

}



/* reference to __meminit __free_pages_bootmem is valid

 * so use __ref to tell modpost not to generate a warning */

void __ref put_page_bootmem(struct page *page)

void put_page_bootmem(struct page *page)

{

	unsigned long type;

	static DEFINE_MUTEX(ppb_lock);



	type = (unsigned long) page->lru.next;

	BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
@@ -116,17 +113,8 @@ void __ref put_page_bootmem(struct page *page) 
		ClearPagePrivate(page);

		set_page_private(page, 0);

		INIT_LIST_HEAD(&page->lru);



		/*

		 * Please refer to comment for __free_pages_bootmem()

		 * for why we serialize here.

		 */

		mutex_lock(&ppb_lock);

		__free_pages_bootmem(page, 0);

		mutex_unlock(&ppb_lock);

		totalram_pages++;

		free_reserved_page(page);

	}



}



#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE

mm/page_alloc.c

+1 −8
Original line number Diff line number Diff line
@@ -745,14 +745,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) 
	local_irq_restore(flags);

}



/*

 * Read access to zone->managed_pages is safe because it's unsigned long,

 * but we still need to serialize writers. Currently all callers of

 * __free_pages_bootmem() except put_page_bootmem() should only be used

 * at boot time. So for shorter boot time, we shift the burden to

 * put_page_bootmem() to serialize writers.

 */

void __meminit __free_pages_bootmem(struct page *page, unsigned int order)

void __init __free_pages_bootmem(struct page *page, unsigned int order)

{

	unsigned int nr_pages = 1 << order;

	unsigned int loop;

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