On (23/09/11 15:34), Pankaj Raghav wrote: > Batching reduces the time of writeback of 4G data to a nvme backing device > from 68 secs to 15 secs (more than **4x improvement**). I don't think anyone does that on practice. Excessive writeback wears out flash storage, so on practice no one writebacks gigabytes of data all at once, but instead people put daily writeback limits and try to be flash storage "friendly", which is especially important if your device has to a lifespan of 7 or 10 years. IOW usually writeback is put under such constraints that writeback speed is hardly noticeable. So I'm not sure that the complexity that this patch introduces is justified, to be honest.
