On 16/2/07 10:54, "Andrew Morton" <akpm at linux-foundation.org> wrote: > OK, you're screwed. I agree that the process freezer is the way out of that > one. > > Ingo said that he's clocked the freezer at a few milliseconds. But if it's > any higher than that it'll need to get sped up once we convert cpu hotplug > to use it. A few milliseconds is acceptable. Presumably that is under some stress workload? What we'd really like is to be able to gang-hotplug CPUs to amortise the freezer overhead. This initial patchset does not include save/restore support anyway, so in fact it would be consistent to have CONFIG_PREEMPT configurable. I'm sure that we are going to have some nasty bugs to fix up as a result, but we can't fix them until we find them! Then we can convert our save/restore code to use the freezer before submitting it for inclusion. -- Keir
