On Thu, May 29, 2014 at 11:05:43AM +0200, Paolo Valente wrote: > This patch is basically the counterpart of patch 13 for NCQ-capable > rotational devices. Exactly as patch 13 does on flash-based devices > and for any workload, this patch disables device idling on rotational > devices, but only for random I/O. More precisely, idling is disabled > only for constantly-seeky queues (see patch 7). In fact, only with > these queues disabling idling boosts the throughput on NCQ-capable > rotational devices. > > To not break service guarantees, idling is disabled for NCQ-enabled > rotational devices and constantly-seeky queues only when the same > symmetry conditions as in patch 13, plus an additional one, hold. The > additional condition is related to the fact that this patch disables > idling only for constantly-seeky queues. In fact, should idling be
Wouldn't it make more sense to limit queue depth to one unless the workload can clearly benefit from allowing higher queue depth? And I really think it'd bring more clarity if we just concentrate on rotational devices. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
