Re: How many copies to get from NIC RX to user read()?

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Tue Jul 09 2002 - 18:11:49 EST

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> How many times is data copied between the time that it is received at the
> NIC and when the user's call to read() returns the data?

Optimal case for TCP

NIC->buffer (DMA)
buffer->user (CPU)

IFF the TCP checksum can be done by the card

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