From 170a5a7eb2bf10161197e5490fbc29ca4561aedb Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 3 Jul 2013 15:03:17 -0700 Subject: [PATCH] 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: Jiang Liu Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Yinghai Lu Cc: Wen Congyang Cc: Tang Chen Cc: Yasuaki Ishimatsu Cc: Mel Gorman Cc: Minchan Kim Cc: "Michael S. Tsirkin" Cc: Cc: Arnd Bergmann Cc: Catalin Marinas Cc: Chris Metcalf Cc: David Howells Cc: Geert Uytterhoeven Cc: Jeremy Fitzhardinge Cc: Jianguo Wu Cc: Joonsoo Kim Cc: Kamezawa Hiroyuki Cc: Konrad Rzeszutek Wilk Cc: Marek Szyprowski Cc: Michel Lespinasse Cc: Rik van Riel Cc: Rusty Russell Cc: Tejun Heo Cc: Will Deacon Cc: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/mm/init_64.c | 18 ++---------------- mm/memory_hotplug.c | 16 ++-------------- mm/page_alloc.c | 9 +-------- 3 files changed, 5 insertions(+), 38 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index b7bdf7bebf3b..ec312a92b137 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -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) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6096cb918735..814ecb2d262f 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -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 diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 93f292a60cb0..2437a7e17aba 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -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; -- GitLab