From f5138e42211d4e8bfbd6ac5b3816348da1533433 Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Thu, 12 Jan 2012 17:20:23 -0800 Subject: [PATCH] kdump: add udev events for memory online/offline 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" [sfr@canb.auug.org.au: fixups for class to subsystem conversion] Signed-off-by: Michael Holzheu Cc: Heiko Carstens Cc: Vivek Goyal Cc: "Eric W. Biederman" Cc: Kay Sievers Cc: Dave Hansen Cc: Martin Schwidefsky Cc: Greg KH Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/memory.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index f17e3ea041c0..ed5de58c340f 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -295,11 +295,22 @@ static int memory_block_change_state(struct memory_block *mem, ret = memory_block_action(mem->start_section_nr, to_state); - if (ret) + if (ret) { mem->state = from_state_req; - else - mem->state = to_state; + goto out; + } + mem->state = to_state; + switch (mem->state) { + case MEM_OFFLINE: + kobject_uevent(&mem->dev.kobj, KOBJ_OFFLINE); + break; + case MEM_ONLINE: + kobject_uevent(&mem->dev.kobj, KOBJ_ONLINE); + break; + default: + break; + } out: mutex_unlock(&mem->state_mutex); return ret; -- 2.34.1