Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754008AbbHMUkG (ORCPT ); Thu, 13 Aug 2015 16:40:06 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:53860 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752183AbbHMUkE (ORCPT ); Thu, 13 Aug 2015 16:40:04 -0400 Date: Thu, 13 Aug 2015 13:40:03 -0700 From: Andrew Morton To: David Vrabel Cc: , , Daniel Kiper , , "Boris Ostrovsky" , Tang Chen , Yasuaki Ishimatsu Subject: Re: [Xen-devel] [PATCHv3 01/10] mm: memory hotplug with an existing resource Message-Id: <20150813134003.895cd1ce421631fb55db21fb@linux-foundation.org> In-Reply-To: <55CC6FB7.4080600@citrix.com> References: <1438275792-5726-1-git-send-email-david.vrabel@citrix.com> <1438275792-5726-2-git-send-email-david.vrabel@citrix.com> <55CC6FB7.4080600@citrix.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3986 Lines: 124 On Thu, 13 Aug 2015 11:21:43 +0100 David Vrabel wrote: > On 30/07/15 18:03, David Vrabel wrote: > > 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. > > Ping? This enables a useful feature for Xen guests. > Looks OK to me. I've cc'ed some memory_hotplug.c developers. If they're OK with it, please add the patch to the (Xen?) tree which uses it. 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 003dbe4..169770a 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1224,23 +1224,21 @@ 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; @@ -1290,6 +1288,22 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/