Loopback and Nagle's algorithm

From: Adam McLaurin
Date: Mon Apr 11 2011 - 22:38:14 EST

I understand that disabling Nagle's algorithm via TCP_NODELAY will
generally degrade throughput. However, in my scenario (150 byte
messages, sending as fast as possible), the actual throughput penalty
over the network is marginal (maybe 10% at most).

However, when I disable Nagle's algorithm when connecting over loopback,
the performance hit is *huge* - 10x reduction in throughput.

The question is, why is disabling Nagle's algorithm on loopback so much
worse w.r.t. throughput? Is there anything I can do to reduce the
incurred throughput penalty?

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/