Subject: paper on fine-grained OS timers
To: None <,,>
From: Mohit Aron <>
List: tech-net
Date: 10/12/1999 10:52:38
	I'd like to tell the BSD community about my paper entitled 
"Soft timers: efficient microsecond software timer support for network
processing" that's going to appear in SOSP 1999. The abstract for the paper
is attached below. The gzip'd postcript for the paper can be downloaded from:


- Mohit


This paper proposes and evaluates soft timers, a new operating
system facility that allows the efficient scheduling of software
events at a granularity down to tens of microseconds.  Soft timers can
be used to avoid interrupts and reduce context switches associated
with network processing without sacrificing low communication delays.

More specifically, soft timers enable transport protocols like TCP to
efficiently perform rate-based clocking of packet transmissions.
Experiments show that rate-based clocking can improve HTTP response
time over connections with high bandwidth-delay products by up to 89%
and that soft timers allow a server to employ rate-based clocking with
little CPU overhead (2--6%) at high aggregate bandwidths.

Soft timers can also be used to perform network polling, which
eliminates network interrupts and increases the memory access locality
of the network subsystem without sacrificing delay. Experiments show
that this technique can improve the throughput of a Web server by up
to 25%.