Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932826AbcKBGbi (ORCPT ); Wed, 2 Nov 2016 02:31:38 -0400 Received: from mga04.intel.com ([192.55.52.120]:61709 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754676AbcKBGas (ORCPT ); Wed, 2 Nov 2016 02:30:48 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,583,1473145200"; d="scan'208";a="896735271" From: Liang Li To: mst@redhat.com, dave.hansen@intel.com Cc: pbonzini@redhat.com, amit.shah@redhat.com, quintela@redhat.com, dgilbert@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, virtio-dev@lists.oasis-open.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, mgorman@techsingularity.net, cornelia.huck@de.ibm.com, Liang Li , Andrew Morton Subject: [PATCH kernel v4 3/7] mm: add a function to get the max pfn Date: Wed, 2 Nov 2016 14:17:23 +0800 Message-Id: <1478067447-24654-4-git-send-email-liang.z.li@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1478067447-24654-1-git-send-email-liang.z.li@intel.com> References: <1478067447-24654-1-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 Content-Length: 1741 Lines: 53 Expose the function to get the max pfn, so it can be used in the virtio-balloon device driver. Simply include the 'linux/bootmem.h' is not enough, if the device driver is built to a module, directly refer the max_pfn lead to build failed. Signed-off-by: Liang Li Cc: Andrew Morton Cc: Mel Gorman Cc: Michael S. Tsirkin Cc: Paolo Bonzini Cc: Cornelia Huck Cc: Amit Shah Cc: Dave Hansen --- include/linux/mm.h | 1 + mm/page_alloc.c | 10 ++++++++++ 2 files changed, 11 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index a92c8d7..f47862a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1772,6 +1772,7 @@ static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd) extern void free_area_init_node(int nid, unsigned long * zones_size, unsigned long zone_start_pfn, unsigned long *zholes_size); extern void free_initmem(void); +extern unsigned long get_max_pfn(void); /* * Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8fd42aa..12cc8ed 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4428,6 +4428,16 @@ void show_free_areas(unsigned int filter) show_swap_cache_info(); } +/* + * The max_pfn can change because of memory hot plug, so it's only good + * as a hint. e.g. for sizing data structures. + */ +unsigned long get_max_pfn(void) +{ + return max_pfn; +} +EXPORT_SYMBOL(get_max_pfn); + static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) { zoneref->zone = zone; -- 1.8.3.1