Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751693AbaANSYx (ORCPT ); Tue, 14 Jan 2014 13:24:53 -0500 Received: from relay2.sgi.com ([192.48.179.30]:34600 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751342AbaANSYv (ORCPT ); Tue, 14 Jan 2014 13:24:51 -0500 From: Nathan Zimmer Cc: Nathan Zimmer , Andrew Morton , Tang Chen , Wen Congyang , Kamezawa Hiroyuki , Yasuaki Ishimatsu , "Rafael J. Wysocki" , Hedi , Mike Travis , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [RFC] hotplug, memory: move register_memory_resource out of the lock_memory_hotplug Date: Tue, 14 Jan 2014 12:24:34 -0600 Message-Id: <1389723874-32372-1-git-send-email-nzimmer@sgi.com> X-Mailer: git-send-email 1.8.2.1 To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We don't need to do register_memory_resource() since it has its own lock and doesn't make any callbacks. Also register_memory_resource return NULL on failure so we don't have anything to cleanup at this point. The reason for this rfc is I was doing some experiments with hotplugging of memory on some of our larger systems. While it seems to work, it can be quite slow. With some preliminary digging I found that lock_memory_hotplug is clearly ripe for breakup. It could be broken up per nid or something but it also covers the online_page_callback. The online_page_callback shouldn't be very hard to break out. Also there is the issue of various structures(wmarks come to mind) that are only updated under the lock_memory_hotplug that would need to be dealt with. cc: Andrew Morton cc: Tang Chen cc: Wen Congyang cc: Kamezawa Hiroyuki cc: Yasuaki Ishimatsu cc: "Rafael J. Wysocki" cc: Hedi cc: Mike Travis cc: linux-mm@kvack.org cc: linux-kernel@vger.kernel.org --- mm/memory_hotplug.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 1ad92b4..62a0cd1 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1097,17 +1097,18 @@ int __ref add_memory(int nid, u64 start, u64 size) struct resource *res; int ret; - lock_memory_hotplug(); - res = register_memory_resource(start, size); ret = -EEXIST; if (!res) - goto out; + return ret; { /* Stupid hack to suppress address-never-null warning */ void *p = NODE_DATA(nid); new_pgdat = !p; } + + lock_memory_hotplug(); + new_node = !node_online(nid); if (new_node) { pgdat = hotadd_new_pgdat(nid, start); -- 1.8.2.1 -- 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/