On Fri, 2008-05-09 at 01:17 +0200, Johannes Berg wrote: > > > That's not really related to wireless at all, if you want to do > > > zero-copy IO then you need to checksum when the stuff hits the wire > > > which means out of hardware buffers, which some hardware (including > > > 802.11) doesn't support so you need to copy, nothing wireless specific > > > here :) > > > > > > > The FCS/CRS checksum of the wireless packet is performed in the HW but > > why should I care about IP layer? > > Because the data you're sending is sent via TCP? Basically, it boils down to this: If you want to checksum the data in software then you need to checksum a snapshot of the data and not allow the application to modify it after you have checksummed it, so you need to make a copy and then checksum it after copying. But if you're making a copy anyway, you can put it all into one buffer too. johannes
Attachment:
signature.asc
Description: This is a digitally signed message part
