DragonFly BSD Digest

Jeroen Ruigrok posted some links to papers about checkpointing and threads:

A User-level Checkpointing Library for POSIX Threads Programs:
http://citeseer.nj.nec.com/james99userlevel.html

Checkpointing and its applications:
http://citeseer.nj.nec.com/wang95checkpointing.html

Migratory applications:
http://citeseer.nj.nec.com/bharat95migratory.html

Kip Macy brought up the idea of moving FreeBSD’s ataNG into DragonFly; the consensus so far is to bring it in separately from the existing ata support, since ataNG’s not yet completely stable.

Thursday October 23, 306 Soda Hall 6 – 8 PM. Matt Dillon will be talking to whomever shows up to the CSUA meeting.

Hiten Pandya brought up futexes for possible inclusion in DragonFly, pointing at this page for reference.

Bill Huey brought up http://people.redhat.com/drepper/futex.pdf, with the caveat that futexes are used for 1:1 threading models, not M:N models such as DragonFly is using/will be using.

Jeroen Ruigrok posted a whole pile of links to routing information for anyone wanting to work on it:

Basics:

TCP Vegas: End to End Congestion Avoidance on a Global Internet
http://citeseer.nj.nec.com/brakmo95tcp.html

Evaluation of TCP Vegas: Emulation and Experiment
http://citeseer.nj.nec.com/ahn95evaluation.html

TCP and Successive Fast Retransmits
http://citeseer.nj.nec.com/floyd95tcp.html

Congestion Avoidance and Control
http://citeseer.nj.nec.com/jacobson88congestion.html

Performance Problems in BSD4.4 TCP
http://citeseer.nj.nec.com/brakmo95performance.html

Comparison of Tahoe, Reno, and SACK
http://citeseer.nj.nec.com/fall95comparisons.html

TCP Vegas: New Techniques for Congestion Detection and Avoidance
http://citeseer.nj.nec.com/brakmo94tcp.html

A Tree-based Packet Routing Table for Berkeley Unix
http://www.cs.berkeley.edu/~sklower/routing.ps

Newer:

TCP Vegas Revisited
http://citeseer.nj.nec.com/hengartner00tcp.html

Analysis on TCP Vegas and TCP Reno
http://citeseer.nj.nec.com/hellal00analysis.html

Scalable Timers for Soft State Protocols
http://citeseer.nj.nec.com/48810.html

End-to-End Internet Packet Dynamics
http://citeseer.nj.nec.com/paxson97endtoend.html

End-to-End Routing Behavior in the Internet
http://citeseer.nj.nec.com/3573.html

Routing with a Clue
http://citeseer.nj.nec.com/afek99routing.html

IP Lookups using Multiway and Multicolumn Search
http://citeseer.nj.nec.com/lampson98ip.html

Fast and Scalable Layer Four Switching
http://citeseer.nj.nec.com/srinivasan98fast.html

High-Speed Policy-based Packet Forwarding Using Efficient
Multi-dimensional Range Matching
http://citeseer.nj.nec.com/lakshman98highspeed.html

Fast Address Lookups using Controlled Prefix Expansion
http://citeseer.nj.nec.com/srinivasan99fast.html

Matt Dillon’s made a diary update.

David P. Reese posted his 9th step into syscall separation, and noted that there remains:

• “37 more uses of stackgap allocations in the linux emulation code”
  
• “26 more 43bsd syscalls that require relocation”
  

Kip Macy’s checkpointing code has been committed; I’m pasting Matt Dillon’s post about it as there’s a lot of issues to consider.

For those of you late to the party, checkpointing allows you to “freeze” a copy of an application so that, in theory, you can restore the program to that running state at a later point in time. Useful, for instance, if you have a program that takes a long time to complete and you don’t want to have to restart from the beginning if there’s an interruption.
Continue reading “Checkpointing is in”

David Cuthbert brought up the idea of Doxygen headers for the source; Matt Dillon didn’t care for the idea, pointing at this for an example. Hiten Pandya noted that he’d like to have a separate by-hand handbook, for which Eirik Nygaard posted a possible example. Matthew Fuller added that he is working on a SGML application for library documentation as part of another project.

While noting that he has made a number of changes to the scheduler, Matt Dillon described a new tool called ‘wmake’. wmake allows you to run make in a subdirectory simulating a buildworld environment, without actually having to build world.

(quoted from his post, using libkvm for an example:)
cd /usr/lib/libkvm
wmake obj
wmake
make install


Joshua Coombs has an extensive writeup of his ideas for routing, located at http://www.outofspec.com/routing/

While talking about something else, Hiten Pandya mentioned the steps necessary to turn on profiling, to help catch bugs. I’ve saved the steps here, in case they are useful…
Continue reading “How to profile”

Emiel Kollof noted that it would be nice if the splash screen loaders could read gzipped files, so that any splash screens could be stored in a compressed format and still used. Hiten Pandya pointed at kern/imgact_gzip.c and boot/i386/kgzldr/boot.c for examples, if anyone wants to tackle this project.

David Leimbach noted that Ron Minnich was porting Plan 9 namespaces to FreeBSD, which duplicates some of the security features to be covered by VFS. Ron Minnich’s web page has more data on this and other technologies.

usr/share/examples/splash has been committed. This is the logo screen Emiel Kollof made from the DragonFly logo.

Emiel Kollof’s also got the NVIDIA binary video driver working; it should show up in dfports.

Hiten Pandya (hmp@backplane.com) is looking for anyone using a AMI MegaRAID card, who is willing to test a patch for FreeBSD-4/DragonFly.