Re: [linux-pm] [PATCH] hibernation should work ok with memory hotplug

KAMEZAWA Hiroyuki
2008-11-06T01:17:51Z

On Thu, 6 Nov 2008 09:14:41 +0900
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:

> Ok, please consider "when memory hotplug happens."
>
> In general, it happens when
> 1. memory is inserted to slot.
> 2. the firmware notifes the system to enable already inserted memory.
>
> To trigger "1", you have to open cover of server/pc. Do you open pc while the system
> starts hibernation ? for usual people, no.
>
> To trigger "2", the user have special console to tell firmware "enable this memory".
> Such firmware console or users have to know "the system works well." And, more important,
> when the system is suspended, the firmware can't do hotplug because the kernel is sleeping.
> So, such firmware console or operator have to know the system status.
>
> Am I missing some ? Current linux can know PCI/USB hotplug while the system is suspended ?
>
*OFFTOPIC*

I hear following answer from my friend.

- hibernate the system
=> plug USB memory
=> wake up the system
=> panic.
- hibernate the system
=> unplug USB memory
=> wake up the sytem
=> panic.

Thanks,
-Kame