> drivers. Is there a reason all of these counting facilities are not > enabled by default in GENERIC kernels? Does using these counters impose such > a > performance penalty that general use was deemed too crippling?
Do you try any benchmark? (by ttcp(1) etc.) During mec(4) (on sgimips O2) debugging, enabling evcnts made network xfer notably slower, but probably it depends on how many counters the driver has and how often they are called. I think we need benchmark results per interfaces rather than blindly enabling counters, because most ordinary users don't care driver internals but just visible xfer rates. --- Izumi Tsutsui
