[Q] e1000 hardware checksumming support?

[Q] e1000 hardware checksumming support?

[Roy Sigurd Karlsbakk]

hi

Can Linux 2.4 use the hardware checksumming in the e1000 adapter? I mean .. my 
server is using most of it's time to csum_partial_copy_generic (and that's 
the checksum? or am I wrong?)

[root@vs1 /]# readprofile | sort -rn +2 | head -30
124855 default_idle                             1950.8594
 33335 handle_IRQ_event                         231.4931
 47663 csum_partial_copy_generic                205.4440
 13144 e1000_intr                               136.9167
  6526 fget                                     101.9688
  6474 system_call                              101.1562
  4620 sock_poll                                 96.2500
 10125 skb_release_data                          90.4018

thanks

roy
-- 
Roy Sigurd Karlsbakk, Datavaktmester
ProntoTV AS - http://www.pronto.tv/
Tel: +47 9801 3356

Computers are like air conditioners.
They stop working when you open Windows.

Re: [Q] e1000 hardware checksumming support?

[David S. Miller]

   From: Roy Sigurd Karlsbakk <roy@karlsbakk.net>
   Date: Wed, 16 Oct 2002 16:54:05 +0200
   
   Can Linux 2.4 use the hardware checksumming in the e1000 adapter?

Two things:

1) On output you only get checksumming if your applications
   use sendfile()

2) On input, since we have to copy the data anyways, we use
   csum_partial_copy because it costs the same as a memcpy.

   Actually, on some x86 cpus the checksum+copy is faster
   than the memcpy, but that is being fixed in current 2.5.x