The primary goal of this research is to improve the scalability and
robustness of the Linux operating system to support greater network server
workloads more reliably.
We are specifically interested in single-system scalability, performance,
and reliability of network server infrastructure products running on Linux,
such as LDAP directory servers, IMAP electronic mail servers, and web
servers, among others.
We're continuing to work with vendors such as Sun and IBM
on their Linux scalability issues.
We've provided several significant modifications to
the Linux kernel.
We attended the 2000 Usenix technical conference, and
presented three papers.
We're continuing to reach out to potential sponsors.
Work continues on long-term projects.
Stephen Molloy is spending his summer in Austin, Texas,
interning at the Austin IBM lab.
Stephen is completing Linux scheduler work he started at CITI.
Randy Appleton of Northern Michigan University was
unable to join us this summer.
Chuck plans to implement the POSIX fadvise()
system call in hopes that Randy can analyze it at some
The NFSv4 project will complete at the
end of August.
A complete snapshot release of the Linux NFSv4 implementation
will be made available at this time.
Meanwhile, the project is preparing to participate in the
July 12 bake-off.
Andy is working on file locking, while
Kendrick completes support for delegation.
Jim Rees and Dug Song are preparing an OpenBSD
port of NFSv4 for the bake-off in July.
Follow-on work is being pursued.
NFSv4 project site
for more information.
Niels, Chuck, and Stephen presented three papers in
the Freenix track at this summer's Usenix technical
Freenix track proceedings
for more information.
While at the conference,
CITI staff met with members of the Linux kernel development
community to discuss future research directions and funding
CITI will increase its presense at upcoming conferences,
including the San Jose Linux Expo, ALS, and OLS.
Niels' /dev/poll implementation has garnered
praise and attention from the Linux community.
We are preparing a version of this work for inclusion in the 2.4
Both paper submissions to October's Atlanta Linux Symposium
were accepted. One paper reports on our continuing
study of POSIX RT signals, while the other paper
analyzes the performance of kernel hash tables.
Chuck continues analyzing and improving phhttpd,
a POSIX RT signals-based server written by Zach Brown.
This work will provide a better picture of performance,
scalability, and usability issues surrounding network
server applications that build their event core using
POSIX RT signals.
Zach has accepted Chuck's patches into the phhttpd
Inessa is studying mmap() scalability issues.
When many mapped objects exist in an address space,
mmap() slows down linearly looking for an
unused address for a new mapping.
Benchmarks and solutions are in the works.
Will Morris has agreed to replace Claire Hough as Chuck's
Netscape manager. Chuck plans to meet with Will and
his boss, Stephen Borcich, in August to discuss ways to
move the project forward.
CITI and LSP sponsors are assembling a one-day workshop on
Linux network server scalability issues of interest to
researchers and industry.
More news to follow.
We continue to pursue research relationships with
Red Hat Software, Silicon Graphics Incorporated, and the
Stichting NLNet Foundation.
If you have comments or suggestions, email
linux-scalability @ citi.umich.edu