From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liang Li Subject: [PATCH v2 repost 6/7] mm: add the related functions to get free page info Date: Wed, 27 Jul 2016 09:23:35 +0800 Message-ID: <1469582616-5729-7-git-send-email-liang.z.li__9455.99646443061$1469583145$gmane$org@intel.com> References: <1469582616-5729-1-git-send-email-liang.z.li@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1469582616-5729-1-git-send-email-liang.z.li@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: linux-kernel@vger.kernel.org Cc: virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org, Amit Shah , Liang Li , qemu-devel@nongnu.org, dgilbert@redhat.com, linux-mm@kvack.org, "Michael S. Tsirkin" , Paolo Bonzini , Andrew Morton , virtualization@lists.linux-foundation.org, Mel Gorman , Vlastimil Babka List-Id: virtualization@lists.linuxfoundation.org Save the free page info into a page bitmap, will be used in virtio balloon device driver. Signed-off-by: Liang Li Cc: Andrew Morton Cc: Vlastimil Babka Cc: Mel Gorman Cc: Michael S. Tsirkin Cc: Paolo Bonzini Cc: Cornelia Huck Cc: Amit Shah --- mm/page_alloc.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7da61ad..3ad8b10 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4523,6 +4523,52 @@ unsigned long get_max_pfn(void) } EXPORT_SYMBOL(get_max_pfn); +static void mark_free_pages_bitmap(struct zone *zone, unsigned long start_pfn, + unsigned long end_pfn, unsigned long *bitmap, unsigned long len) +{ + unsigned long pfn, flags, page_num; + unsigned int order, t; + struct list_head *curr; + + if (zone_is_empty(zone)) + return; + end_pfn = min(start_pfn + len, end_pfn); + spin_lock_irqsave(&zone->lock, flags); + + for_each_migratetype_order(order, t) { + list_for_each(curr, &zone->free_area[order].free_list[t]) { + pfn = page_to_pfn(list_entry(curr, struct page, lru)); + if (pfn >= start_pfn && pfn <= end_pfn) { + page_num = 1UL << order; + if (pfn + page_num > end_pfn) + page_num = end_pfn - pfn; + bitmap_set(bitmap, pfn - start_pfn, page_num); + } + } + } + + spin_unlock_irqrestore(&zone->lock, flags); +} + +int get_free_pages(unsigned long start_pfn, unsigned long end_pfn, + unsigned long *bitmap, unsigned long len) +{ + struct zone *zone; + int ret = 0; + + if (bitmap == NULL || start_pfn > end_pfn || start_pfn >= max_pfn) + return 0; + if (end_pfn < max_pfn) + ret = 1; + if (end_pfn >= max_pfn) + ret = 0; + + for_each_populated_zone(zone) + mark_free_pages_bitmap(zone, start_pfn, end_pfn, bitmap, len); + return ret; +} +EXPORT_SYMBOL(get_free_pages); + static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) { zoneref->zone = zone; -- 1.9.1