Hi, Thanks, hope the patch works alright... > I'm not convinced this is the best value for the default case. > If the server can handle operations fast enough that the queue > remains at 1, coalescing doesn't seem necessary, and it will give > widely varied timings for some of the operations of some clients. I think in general this is a good value, but change it if you like.
If the disk is fast enough that the queue remains at 1 the loss is small (depending on the processing time), however you are right it slows the first one down. Argument for setting it to 1: We want to coalesce as much ops as possible, assume each sync costs 5 ms (disk access time) while a non-blocking modification might take 0.1ms. If somebody has 2 ops in the queue and the low watermark is 2 the first finishes on 5.1 ms, while the second finishes on 10.2 ms. In case the watermark is 1 the first and the second one finishs at 5.2 ms. Even if you assume that the op might be blocking I would say for the majority of people setting it to 1 reduce the overall op time. julian _______________________________________________ Pvfs2-developers mailing list [email protected] http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers
