From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755166Ab1J0Jcv (ORCPT ); Thu, 27 Oct 2011 05:32:51 -0400 Received: from mtagate2.uk.ibm.com ([194.196.100.162]:55704 "EHLO mtagate2.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751728Ab1J0Jcu (ORCPT ); Thu, 27 Oct 2011 05:32:50 -0400 Message-ID: <1319707965.2830.1.camel@br98xy6r> Subject: [PATCH] kdump: Add udev events for memory online/offline From: Michael Holzheu Reply-To: holzheu@linux.vnet.ibm.com To: akpm@linux-foundation.org Cc: Heiko Carstens , Vivek Goyal , "Eric W. Biederman" , schwidefsky@de.ibm.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Kay Sievers , Dave Hansen Date: Thu, 27 Oct 2011 11:32:45 +0200 In-Reply-To: <20111027073058.GA2422@osiris.boeblingen.de.ibm.com> References: <1319645292.3321.24.camel@br98xy6r> <20111026192449.GE355@redhat.com> <20111027073058.GA2422@osiris.boeblingen.de.ibm.com> Organization: IBM Content-Type: text/plain; charset="us-ascii" X-Mailer: Evolution 3.2.0- Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michael Holzheu Currently no udev events for memory hotplug "online" and "offline" are generated: # udevadm monitor # echo offline > /sys/devices/system/memory/memory4/state ==> No event When kdump is loaded, kexec detects the current memory configuration and stores it in the pre-allocated ELF core header. Therefore, for kdump it is necessary to reload the kdump kernel with kexec when the memory configuration changes (e.g. for online/offline hotplug memory). In order to do this automatically, udev rules should be used. This kernel patch adds udev events for "online" and "offline". Together with this kernel patch, the following udev rules for online/offline have to be added to "/etc/udev/rules.d/98-kexec.rules": SUBSYSTEM=="memory", ACTION=="online", PROGRAM="/etc/init.d/kdump restart" SUBSYSTEM=="memory", ACTION=="offline", PROGRAM="/etc/init.d/kdump restart" Signed-off-by: Michael Holzheu --- drivers/base/memory.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -310,11 +310,15 @@ store_mem_state(struct sys_device *dev, mem = container_of(dev, struct memory_block, sysdev); - if (!strncmp(buf, "online", min((int)count, 6))) + if (!strncmp(buf, "online", min((int)count, 6))) { ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE); - else if(!strncmp(buf, "offline", min((int)count, 7))) + if (ret == 0) + kobject_uevent(&dev->kobj, KOBJ_ONLINE); + } else if (!strncmp(buf, "offline", min((int)count, 7))) { ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); - + if (ret == 0) + kobject_uevent(&dev->kobj, KOBJ_OFFLINE); + } if (ret) return ret; return count;