Updating our TCP and socket sysctl values...
bf1783 at googlemail.com
Thu Aug 25 15:53:02 UTC 2011
> >> I believe it's time to up these values to something that's in line with higher speed
> >> local networks, such as 10G. Perhaps it's time to move these to 2MB instead of 256K.
> >> Thoughts?
> > This never happened, did it? Was there a reason?
> I went back and looked at the mail thread. I didn't see any strong objections
> so I think you should commit this for 9.x.
> np@ did point out that nmbclusters also lags on modern hardware so consider upping
> that at the same time.
I thought Bruce's observation, in:
"...there is an mostly-unrelated bufferbloat problem that is
purely local. If you have a buffer that is larger than an Ln cache (or
about half than), then actually using just a single buffer of that size
guarantees thrashing of the Ln cache, so that almost every memory access
is an Ln cache miss. Even with current hardware, a buffer of size 256K
will thrash most L1 caches and a buffer of size a few MB will thrash most
, and his suggestion for some sort of auto-tuning, deserve
consideration. Are you going to address this problem (at least the L2
and higher cache thrashing), or give some suggestions for tuning in
UPDATING and the relevant manpages?
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