From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: [PATCHv2 01/10] mm: memory hotplug with an existing resource Date: Fri, 24 Jul 2015 12:47:39 +0100 Message-ID: <1437738468-24110-2-git-send-email-david.vrabel__20730.5832919248$1437738574$gmane$org@citrix.com> References: <1437738468-24110-1-git-send-email-david.vrabel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZIbSf-0007f3-6v for xen-devel@lists.xenproject.org; Fri, 24 Jul 2015 11:48:21 +0000 In-Reply-To: <1437738468-24110-1-git-send-email-david.vrabel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xenproject.org Cc: Daniel Kiper , linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Vrabel , Boris Ostrovsky , Andrew Morton List-Id: xen-devel@lists.xenproject.org Add add_memory_resource() to add memory using an existing "System RAM" resource. This is useful if the memory region is being located by finding a free resource slot with allocate_resource(). Xen guests will make use of this in their balloon driver to hotplug arbitrary amounts of memory in response to toolstack requests. Signed-off-by: David Vrabel Cc: Andrew Morton --- include/linux/memory_hotplug.h | 2 ++ mm/memory_hotplug.c | 28 +++++++++++++++++++++------- 2 files changed, 23 insertions(+), 7 deletions(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 6ffa0ac..c76d371 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -11,6 +11,7 @@ struct zone; struct pglist_data; struct mem_section; struct memory_block; +struct resource; #ifdef CONFIG_MEMORY_HOTPLUG @@ -266,6 +267,7 @@ static inline void remove_memory(int nid, u64 start, u64 size) {} extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, void *arg, int (*func)(struct memory_block *, void *)); extern int add_memory(int nid, u64 start, u64 size); +extern int add_memory_resource(int nid, struct resource *resource); extern int zone_for_memory(int nid, u64 start, u64 size, int zone_default); extern int arch_add_memory(int nid, u64 start, u64 size); extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 26fbba7..460d0fe 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1216,23 +1216,21 @@ int zone_for_memory(int nid, u64 start, u64 size, int zone_default) } /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ -int __ref add_memory(int nid, u64 start, u64 size) +int __ref add_memory_resource(int nid, struct resource *res) { + u64 start, size; pg_data_t *pgdat = NULL; bool new_pgdat; bool new_node; - struct resource *res; int ret; + start = res->start; + size = resource_size(res); + ret = check_hotplug_memory_range(start, size); if (ret) return ret; - res = register_memory_resource(start, size); - ret = -EEXIST; - if (!res) - return ret; - { /* Stupid hack to suppress address-never-null warning */ void *p = NODE_DATA(nid); new_pgdat = !p; @@ -1282,6 +1280,22 @@ out: mem_hotplug_done(); return ret; } +EXPORT_SYMBOL_GPL(add_memory_resource); + +int __ref add_memory(int nid, u64 start, u64 size) +{ + struct resource *res; + int ret; + + res = register_memory_resource(start, size); + if (!res) + return -EEXIST; + + ret = add_memory_resource(nid, res); + if (ret < 0) + release_memory_resource(res); + return ret; +} EXPORT_SYMBOL_GPL(add_memory); #ifdef CONFIG_MEMORY_HOTREMOVE -- 2.1.4