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

KAMEZAWA Hiroyuki
2008-11-06T09:12:58Z

On Thu, 6 Nov 2008 10:12:18 +0100
Pavel Machek <pavel@suse.cz> wrote:

> > 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
Ok. I'll confirm if I have a chance.
Sorry for rumor.

Thanks,
-Kame