On Tue, 12 Feb 2008, Peter Zijlstra wrote: > > > > Rusty - Stop machine. > > After doing a bunch of testing last three days I actually downgraded > > stop machine > > changes from [highly experimental] to simply [experimental]. Pleas see > > this thread > > for more info: http://marc.info/?l=linux-kernel&m=120243837206248&w=2 > > Short story is that I ran several insmod/rmmod workloads on live > > multi-core boxes > > with stop machine _completely_ disabled and did no see any issues. Rusty > > did not get > > a chance to reply yet, I hopping that we'll be able to make "stop > > machine" completely > > optional for some configurations. >
This part really scares me. The comment that you say you have run several insmod/rmmod workloads without kstop_machine doesn't mean that it is still safe. A lot of races that things like this protect may only happen under load once a month. But the fact that it happens at all is reason to have the protection. Before taking out any protection, please analyze it in detail and report your findings why something is not needed. Not just some general hand waving and "it doesn't crash on my box". Besides that, kstop_machine may be used by other features that can have an impact. Again, if you have a system that cant handle things like kstop_machine, than don't do things that require a kstop_machine run. All modules should be loaded, and no new modules should be added when the system is performing critical work. I see no reason for disabling kstop_machine. -- Steve -- 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/
