On Wed, Feb 11, 2015 at 09:21:21PM -0600, Josh Poimboeuf wrote: > Ingo, Peter, > > Would you have any objections to making task_rq_lock/unlock() non-static > (or moving them to kernel/sched/sched.h) so they can be called by the > livepatch code? Basically yes. I really don't want to expose that. And kernel/sched/sched.h is very much not intended for use outside of kernel/sched/ so even that is a no go. > To provide some background, I'm looking for a way to temporarily prevent > a sleeping task from running while its stack is examined, to decide > whether it can be safely switched to the new patching "universe". For > more details see klp_transition_task() in the patch below. > > Using task_rq_lock() is the most straightforward way I could find to > achieve that. Its not at all clear how all this would work to me. And I'm not motivated enough to go try and reverse engineer your patch; IMO livepatching is utter fail. If your infrastructure relies on the uptime of a single machine you've lost already. FWIW, the barriers in klp_update_task_universe() and klp_set_universe_goal() look like complete crack, and their comments are seriously deficient. -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
