On Fri, Feb 23, 2007 at 04:32:01PM +0530, Srivatsa Vaddagiri wrote: > On Fri, Feb 23, 2007 at 04:17:23PM +0530, Srivatsa Vaddagiri wrote: > > Ok that was my point of concern. For hotplug we would ideally like > > everyone to be frozen. If we are not freezing some (like vfork parents), > > (rather if we dont -wait- for them to get frozen) before offlining a > > cpu, then it may expose some hotplug unsafe code in the caller of vfork > > in kernel - hopefully that is not a issue practically speaking. > > I notice that __call_usermodehelper() work function calls kernel_thread with > CLONE_VFORK set. __call_usermodehelper() is usualled called in the > context of a worker thread (kevent).
But I see __call_usermodehelper being called from the context of khelper_wq which is a singlethreaded workqueue. I thought we were not planning to freeze singlethreaded workqueue's for hotplug, since we are not kthread_stopping them anywhere. So this kthread_stop waiting for parent(khelper_wq) which is blocked on wait_for_complete(child->vfork_done) shouldn't occur. No? Thanks and Regards gautham. -- Gautham R Shenoy Linux Technology Center IBM India. "Freedom comes with a price tag of responsibility, which is still a bargain, because Freedom is priceless!" - 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/
