From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx182.postini.com [74.125.245.182]) by kanga.kvack.org (Postfix) with SMTP id B33706B0068 for ; Sat, 16 Mar 2013 13:04:32 -0400 (EDT) Received: by mail-pb0-f50.google.com with SMTP id up1so5091338pbc.9 for ; Sat, 16 Mar 2013 10:04:32 -0700 (PDT) From: Jiang Liu Subject: [PATCH v2, part3 09/12] mm: avoid using __free_pages_bootmem() at runtime Date: Sun, 17 Mar 2013 01:03:30 +0800 Message-Id: <1363453413-8139-10-git-send-email-jiang.liu@huawei.com> In-Reply-To: <1363453413-8139-1-git-send-email-jiang.liu@huawei.com> References: <1363453413-8139-1-git-send-email-jiang.liu@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , David Rientjes Cc: Jiang Liu , Wen Congyang , Mel Gorman , Minchan Kim , KAMEZAWA Hiroyuki , Michal Hocko , Jianguo Wu , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Yinghai Lu , x86@kernel.org, Tang Chen , Yasuaki Ishimatsu Avoid using __free_pages_bootmem() at runtime, so we could easily manage totalram_pages and zone->managed_pages. With this change applied, __free_pages_bootmem() is only used by bootmem.c and nobootmem.c at boot time, so mark it as __init. And other callers of __free_pages_bootmem() have been switched to free_reserved_page(), which handles totalram_pages and zone->managed_pages in a safe 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 free_reserved_page() protects totalram_pages and zone->managed_pages with managed_pages_count_lock, so remove the redundant ppb_lock lock in put_page_bootmem(). This makes the locking rules much more clear. Signed-off-by: Jiang Liu Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Andrew Morton Cc: Yinghai Lu Cc: x86@kernel.org Cc: Wen Congyang Cc: Tang Chen Cc: Yasuaki Ishimatsu Cc: Mel Gorman Cc: Minchan Kim Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org --- 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 05ef3ff..5e19126 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -694,36 +694,22 @@ 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 40c3c78..a1debd0 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); } - } #ifndef CONFIG_SPARSEMEM_VMEMMAP diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9d08d06..b0ca2b7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -740,14 +740,7 @@ 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; -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org