On Wed, 26 Sep 2001, jamal wrote: > Is there any reason you are not using dev_queue_xmit()? (side > benefits, you could hack this into using scatter gather schemes etc) the reason is latency of messages, and reliability of sends. If we are in the middle of a *nasty* crash that takes down the system down 10 microseconds later, then i wanted to make 100% sure the message gets out and the bug can be debugged. The VGA console and the serial logging console have such properties - messages are instantaneous. Networking is very asynchron in nature, so a new network driver extension was needed to achieve this goal. There are crashes where there are no new IRQs processed after the crash, so there is no chance for dev_queue_xmit to do any useful send. We must be able to send packets even if the output interface's hardware queues are full - and dev_queue_xmit relies on future device interrupts to send queued packets. this is not just theory - about 10% of the crashes i experience (during development...) are such, and the majority of the 'hard to fix' crashes have such properties, especially on busy remote servers. Ingo - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
