Hello, On Wed, Sep 16, 2015 at 12:58:00PM +0200, Christian Borntraeger wrote: > FWIW, I added a printk to percpu_down_write. With KVM and uprobes disabled, > just booting up a fedora20 gives me __6749__ percpu_down_write calls on 4.2. > systemd seems to do that for the processes. > > So a revert is really the right thing to do. In fact, I dont know if the > rcu_sync_enter rework is enough. With systemd setting the cgroup seem to > be NOT a cold/seldom case.
Booting would usually be the hottest operation for that and it's still *relatively* cold path compared to the reader side which is task fork/exit paths. The whole point is shift overhead from hotter reader side. Can you see problems with percpu_rwsem rework? Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
