Messages in this thread | | | Date | Sat, 24 Feb 2007 00:33:34 +0530 | From | Gautham R Shenoy <> | Subject | Re: freezer problems |
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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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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