On Thursday 15 June 2006 1:39 am, Pavel Machek wrote: > > > Actually it would be interesting to hear counter-arguments to this > > position: > > > > We already HAVE that two-phase thing going on, at > > least for swsusp. In phase I a PM_EVENT_FREEZE > > gets sent. Then in phase II a PM_EVENT_SUSPEND gets > > tries to really suspend things. > > > > One counter-argument might be that "phase I.5 resumes those devices" > > is a problem. Another might be that "FREEZE should not be sent to > > the console(s), the swap device, or their parents". I suspect there > > are a few more issues mixed up in there too. > > This is FAQ: Which seems to suggest that you are Frequently giving a useless Answer to the Question ... and in this case, not the question which was asked. You're doing that "attack the straw man" thing again. > Q: I do not understand why you have such strong objections to idea of > selective suspend. Not a question, and it's not clear who "you" is. Presumably, "Pavel"? Plus it doesn't relate to the position sketched above. > A: Do selective suspend during runtime power managment, that's > okay. But > its useless for suspend-to-disk. (And I do not see how you could use > it for suspend-to-ram, I hope you do not want that). That's a bunch of non-answers of course. And re the parenthetical comment ... to use ACPI terminology for just a moment (without assuming ACPI!), it's trivially true that there are different device suspend states, and that real system sleep states like S1 and S3 (plus many non-ACPI variants thereof) can accomodate multiple device suspend states. So for example a device enabled as a wakeup event source might use a less aggressive suspend state than one which doesn't need to offer any functionality while the system is in that sleep state. In some cases those "less aggressive suspend" states _are_ exactly equivalent to an un-suspended device. (Not with PCI PM of course, but with some other hardware frameworks.) > Lets see, so you suggest to Actually I asked for counter-arguments to a position, which was intended as a request not to enter the usual flamewar that shows up whenever someone observes that Linux-PM has a few issues that affect swsusp. At this time, I had offered no suggestion. Those flames are, as always, tedious and needless. > * SUSPEND all but swap device and parents > * Snapshot > * Write image to disk > * SUSPEND swap device and parents > * Powerdown > > Oh no, that does not work, Oddly enough, it wasn't even mentioned in the position I was asking a response to. This is what's called a "straw man" attack ... when rather than actually address an issue that's been raised, someone sets up a _different_ issue, attacks that, and than treats the original issue as resolved: http://www.nizkor.org/features/fallacies/straw-man.html Attacking a straw man is as efficaceous as putting pins into a voodoo doll ... at least, in terms of addressing the original question.
