On Thu, Nov 28, 2013 at 12:10:40PM +0100, Paolo Bonzini wrote: > Il 28/11/2013 12:09, Gleb Natapov ha scritto: > > > - if there are no callbacks, but there are readers, synchronize_srcu > > > busy-loops for some time checking if the readers complete. After a > > > while (20 us for synchronize_srcu, 120 us for > > > synchronize_srcu_expedited) it gives up and starts using a workqueue to > > > poll every millisecond. This should never happen unless > > > > Unless what ? :) Unless reader is scheduled out? > > Yes. Or unless my brain is scheduled out in the middle of a sentence. > So we will have to disable preemption in a reader to prevent big latencies for a writer, no? -- Gleb. -- 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
