From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33782) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bICug-0002dS-FS for qemu-devel@nongnu.org; Wed, 29 Jun 2016 06:40:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bICud-0003I0-Aw for qemu-devel@nongnu.org; Wed, 29 Jun 2016 06:40:10 -0400 Received: from mga14.intel.com ([192.55.52.115]:12111) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bICud-0003H1-5w for qemu-devel@nongnu.org; Wed, 29 Jun 2016 06:40:07 -0400 From: Liang Li Date: Wed, 29 Jun 2016 18:32:19 +0800 Message-Id: <1467196340-22079-7-git-send-email-liang.z.li@intel.com> In-Reply-To: <1467196340-22079-1-git-send-email-liang.z.li@intel.com> References: <1467196340-22079-1-git-send-email-liang.z.li@intel.com> Subject: [Qemu-devel] [PATCH v2 kernel 6/7] mm: add the related functions to get free page info List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mst@redhat.com Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, dgilbert@redhat.com, quintela@redhat.com, Liang Li , Andrew Morton , Mel Gorman , Paolo Bonzini , Cornelia Huck , Amit Shah 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: 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 2083b40..c2a6669 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4521,6 +4521,52 @@ 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; -- 1.8.3.1