Messages in this thread | | | Date | Mon, 1 Mar 2010 10:23:27 -0500 (EST) | From | Alan Stern <> | Subject | Re: [linux-pm] Is it supposed to be ok to call del_gendisk while userspace is frozen? |
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On Mon, 1 Mar 2010, Pavel Machek wrote:
> Hi! > > > > > This is a matter for Jens. Is the bdi writeback task freezable? If it > > > > is, should it be made unfreezable? > > > > > > I'm not a big expect on what tasks should be freezable or not. As it > > > stands, the writeback tasks will attempt to freeze and thaw with the > > > system. I guess that screws the sync from resume call, since it's not > > > running and the sync will wait for it to retrieve and finish that work > > > item. > > > > > > To the suspend experts - can we safely mark the writeback tasks as > > > non-freezable? > > > > The reason for freezing those tasks is to avoid writebacks at random > > times during a system sleep transition, when the underlying device may > > already be suspended, right? > > It is also there to avoid inconsistency between in-filesystem data and > snapshot in hibernation image.
A good point, although in this case I think it won't matter. Writing out a dirty page twice (once right after taking the snapshot and then again after resuming from hibernation) will leave the disk in a correct state.
Alan Stern
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