Messages in this thread |  | | | Date | Fri, 20 Jul 2007 16:12:31 -0400 (EDT) | | From | Alan Stern <> | | Subject | Re: [linux-pm] Re: Hibernation considerations |
| |
On Fri, 20 Jul 2007, Oliver Neukum wrote:
> Am Freitag 20 Juli 2007 schrieb Alan Stern: > > Some drivers need the ability to schedule. Some will need the ability > > to allocate memory (although GFP_ATOMIC is probably sufficient). Some > > will need timers to run. > > Some will have to request firmware. It can add up to some megabytes. > In addition, if we don't freeze, some drivers, eg. video drivers, can > do allocations in the megabyte range. > > It seems to me that without the freezer we will end up with many drivers > needing a two step notification process. Furthermore there are requirements > on the order of shutting down system facilities, eg. device addition must > be stopped before drivers allocate firmware.
These are really separate issues, since they refer to things that have to happen well before the memory snapshot is captured.
We already have a pre-suspend notification available for drivers that need to allocate large amounts of memory.
You are correct about the need to delay/stop device addition. I don't know how this can be done in general; each code path calling device_add() may have to be treated individually.
Alan Stern
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |