On Mon, Jul 31, 2006 at 08:35:55PM +1000, Herbert Xu ([EMAIL PROTECTED]) wrote: > Evgeniy Polyakov <[EMAIL PROTECTED]> wrote: > > > >> - if there is space, report it in the ring buffer. Yes, the buffer > >> can be optional, then all events are reported by the system call. > > > > That requires a copy, which can neglect syscall overhead. > > Do we really want it to be done? > > Please note that we're talking about events here, not actual data. So > only the event is being copied, which is presumably rather small compared > to the data.
In syscall time kevents copy 40bytes for each event + 12 bytes of header (number of events, timeout and command number). That's likely two cache lines if only one event is reported. -- Evgeniy Polyakov - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html