On Thu, Mar 17, 2011 at 09:00:30AM +0100, Jean-Philippe Menil wrote: > >>Are you running a preemptible kernel? > >>Does the following help at all? > >> > >>diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c > >>index 2ca4535..cdf51c9 100644 > >>--- a/virt/kvm/eventfd.c > >>+++ b/virt/kvm/eventfd.c > >>@@ -90,7 +90,7 @@ irqfd_shutdown(struct work_struct *work) > >> * We know no new events will be scheduled at this point, so block > >> * until all previously outstanding events have completed > >> */ > >>- flush_work(&irqfd->inject); > >>+ flush_work_sync(&irqfd->inject); > >> > >> /* > >> * It is now safe to release the object's resources > >> > >Hi, > > > >thanks for the response. > > > >root@ayrshire:~# zcat /proc/config.gz | grep -i preempt > ># CONFIG_PREEMPT_RCU is not set > >CONFIG_PREEMPT_NOTIFIERS=y > >CONFIG_PREEMPT_NONE=y > ># CONFIG_PREEMPT_VOLUNTARY is not set > ># CONFIG_PREEMPT is not set > > > >It does not seem to be a preemptible kernel. > > > >I will test tour patch, and report the result. > > > >Regards. > > > Hi, > > i reboot the host with the "flush_work_sync", yesterday at lunchtime. > I haven't see "Eventfd bug detected" or "Wakeup bug detected" until now. > > The modification seem to do the trick. > > So, if my understand is correct, flush_work flush the last irqfd, > but in my case, antoher irqfd was still queued to a cpu? > Is that right? > > Regards. Yes, it says: * flush_work - wait for a work to finish executing the last queueing instance * @work: the work to flush * * Wait until @work has finished execution. This function considers * only the last queueing instance of @work. If @work has been * enqueued across different CPUs on a non-reentrant workqueue or on * multiple workqueues, @work might still be executing on return on * some of the CPUs from earlier queueing. * * If @work was queued only on a non-reentrant, ordered or unbound * workqueue, @work is guaranteed to be idle on return if it hasn't * been requeued since flush started. kvm uses the default workqueue which is non-reentrant. Thanks to Gleb for the suggestion! -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
