Re: TCP prequeue performance

"David S. Miller" [off-list ref] writes:

Not true, if this check does not pass, tp->ucopy.task is
never set, therefore prequeue processing is never performed.

Oh well, here goes my nice theory :)

This test must pass the first time, when both tp->ucopy.task
and user_recv are both NULL, in order for prequeue processing
to occur at all.

So his change did totally disable prequeue.

Then probably his test was latency bound somehow, but normally
that should not affect system time, just wall time.

I would perhaps compare context switch numbers and netstat -s
output between the different runs and see if anything pops out.

-Andi