On Thu, 20 Nov 2014 13:10:12 +0100 Alexander Graf <agraf@xxxxxxx> wrote: > > > On 20.11.14 11:40, Aneesh Kumar K.V wrote: > > "Suresh E. Warrier" <warrier@xxxxxxxxxxxxxxxxxx> writes: > > > >> This patch adds trace points in the guest entry and exit code and also > >> for exceptions handled by the host in kernel mode - hypercalls and page > >> faults. The new events are added to /sys/kernel/debug/tracing/events > >> under a new subsystem called kvm_hv. > > > > ........ > > > >> /* Set this explicitly in case thread 0 doesn't have a vcpu */ > >> @@ -1687,6 +1691,9 @@ static void kvmppc_run_core(struct kvmppc_vcore *vc) > >> > >> vc->vcore_state = VCORE_RUNNING; > >> preempt_disable(); > >> + > >> + trace_kvmppc_run_core(vc, 0); > >> + > >> spin_unlock(&vc->lock); > > > > Do we really want to call tracepoint with spin lock held ? Is that a good > > thing to do ?. > > I thought it was safe to call tracepoints inside of spin lock regions? > Steve? > There's tracepoints in the guts of the scheduler where rq lock is held. Don't worry about it. The tracing system is lockless. -- Steve -- 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
