On Sunday, 8 July 2007 14:09, Pavel Machek wrote: > Hi! > > > > And then you will face the problem of a user task doing I/O during > > > hibernate after the atomic snapshot has been made. > > > > I don't think that this is possible in normal conditions. It would be > > possible > > if, for example, the task were waiting for an unavailable resource and that > > resource became available after the hibernation image had been created. > > In that case, however, to do any damage, the task would have to cause some > > filesystem-related data to be flushed in the same syscall (ie. before > > returning > > to user space). > > I agree that it is relatively unlikely to trigger (if you avoid > freezing the tasks that were uninterruptible for long), but it will > trigger in error cases etc.
Yes, it will. > > Such situations may be prevented by a mechanizm detecting if any > > uniterruptible > > and freezing task has been woken up after creating the image and aborting > > the > > hibernation in that cases. For this purpose, we only need to add an > > appropriate condition to try_to_wake_up() and make it start to trigger > > after, > > for example, enabling the nonboot CPUs. > > I don't know how to do that mechanism... but if we knew where to trap > filesystem writes, we could simply freeze at that point, and at that > point only, no? >From the image/filesystems integrity standpoint, yes, that should be sufficient. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
