Re: slow writes on nfs with bge devices

On Sun, 21 Jan 2007, Max Laier wrote:

On Sunday 21 January 2007 07:25, Bruce Evans wrote:
nfs writes much less well with bge NICs than with other NICs (sk, fxp,

Do you use hardware checksumming on the bge? There is an XXX in
bge_start_locked() that looks a bit suspicious to me.

I use the default for that. Wouldn't checksum problems show up as errors
somwhere?

[excessive quoting deleted]

tcpdump shows a lot of intervals between nfs write requests of almost
exactly 10 mS (even with HZ = 1000, but more obvious with HZ = 100)
for the broken case, so the problem is apparently related to timeouts,
or timeouts are masking a larger problem. (The average interval between
write requests needs to be about 683 uS to avoid wasting any bandwith.
fxp <-> fxp on the same network averages 708 uS. fxp <-> bge 5701
averages 3981.)

Bruce
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