From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161520AbcG0BcC (ORCPT ); Tue, 26 Jul 2016 21:32:02 -0400 Received: from mga03.intel.com ([134.134.136.65]:28635 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932591AbcG0BbP (ORCPT ); Tue, 26 Jul 2016 21:31:15 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,427,1464678000"; d="scan'208";a="146018059" From: Liang Li To: linux-kernel@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, linux-mm@kvack.org, virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org, qemu-devel@nongnu.org, dgilbert@redhat.com, quintela@redhat.com, Liang Li , Andrew Morton , Vlastimil Babka , Mel Gorman , "Michael S. Tsirkin" , Paolo Bonzini , Cornelia Huck , Amit Shah 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@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1469582616-5729-1-git-send-email-liang.z.li@intel.com> References: <1469582616-5729-1-git-send-email-liang.z.li@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.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