On Wed, Jan 20, 2016 at 8:42 PM, Christoph Lameter <cl@xxxxxxxxx> wrote: > On Wed, 20 Jan 2016, Shiraz Hashim wrote: > >> The patch makes vmstat_shepherd deferable which if is quiesed >> would not schedule vmstat update on other cpus. Wouldn't this >> aggravate the problem of vmstat for rest cpus not gettng updated. > > Its only "deferred" in order to make it at the next tick and not cause an > extra event. This means that vmstat will run periodically from tick > processing. It merely causes a synching so that we have one interruption > that does both. > > On idle we fold counters immediately. So there is no loss of accuracy. > vmstat is scheduled by shepherd or by itself (conditionally). In case shepherd is deferred and vmstat doesn't schedule itself, then vmstat needs to wait for shepherd to be up and then schedule it. This may end up in delayed status update for all live cpus. Isn't it ? -- regards Shiraz Hashim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>