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

Pavel Machek
2008-11-06T09:12:18Z

> 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.

That should work. File a bugzilla if it does not.

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

That should work ok as long as you unmount the drive first.
Pavel

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