On Thu, Jan 18, 2001 at 08:24:04PM +0100, A.N.Kuznetsov wrote:
> > 2.4 has most of the infrastructure neededfor that: TCP gets an error code
> > now
> > when the device queue overflows. It currently doesn't send more aggressively
>
> Really it does. rto backoff is not applied in this case and tcp enters
> congestion avoidance rather than to slow start.
>
> In fact local drop is equivalent to ECN, with all its advantages.
Ok for retransmits, but as far as I can see not for first transmits.
In fact the code is racy, packets_out is not incremented and the retransmit
handler bails out when it is zero.
>
>
> What's about SYNs, it is lacune. It should be repaired and this is easy.
It will usually not help because it doesn't change the resolver in the glibc
(most programs resolve names first and depend on these packets). What I
usually do is to use a local dns proxy with more aggressive dns retransmit.
Currently it cannot detect queue drops from user space though.
-Andi
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