Messages in this thread | | | Date | Mon, 11 Mar 2002 12:20:26 +0800 | Subject | Re: Broadcom 5700/5701 Gigabit Ethernet Adapters | From | Michael Clark <> |
| |
On Monday, March 11, 2002, at 11:15 AM, Benjamin LaHaise wrote:
> On Sun, Mar 10, 2002 at 06:30:33PM -0800, David S. Miller wrote: >> Syskonnect sk98 with jumbo frames gets ~107MB/sec TCP bandwidth >> without NAPI, there is no reason other cards cannot go full speed as >> well. >> >> NAPI is really only going to help with high packet rates not with >> thinks like raw bandwidth tests. > > Well, the thing that hurts the 83820 is that its interrupt > mitigation capabilities are rather limited. This is where napi > helps: by turning off the rx interrupt for the duration of packet > processing, cpu cycles aren't wasted on excess rx irqs. > > As to the lack of bandwidth, it stems from far too much interrupt > overhead and the currently braindead attempt at irq mitigation. > Since the last time I worked on it, a number of potential techniques > have come up that should bring it into the 100MB realm (assuming it > doesn't get trampled on by ksoftirqd).
What about jumbo frames? I notice this comment in the driver "disable jumbo frames to avoid tx hangs". I'm getting ~550Mb/sec from a single TCP stream and ~700Mb/sec with 2 in parallel. Jumbo frames would probably improve this quite a bit.
~mc
- 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/
| |