| Date | Mon, 31 Jul 2006 14:50:37 +0400 | From | Evgeniy Polyakov <> | Subject | Re: [RFC 1/4] kevent: core files. |
| |
On Mon, Jul 31, 2006 at 08:35:55PM +1000, Herbert Xu (herbert@gondor.apana.org.au) wrote: > Evgeniy Polyakov <johnpol@2ka.mipt.ru> 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 linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|