Planet FreeBSD

Chemnitz Linux Days 2012

2012-02-05T00:55:02Z

Chemnitz Linux Days 2012 (http://chemnitzer.linux-tage.de/2012/info/), Chemnitz University of Technology, Chemnitz, Germany 17 - 18 March, 2012. Chemnitz Linux Days is a conference that deals with Linux and Open Source software. It is open for everyone - newbies and experts alike. This event is organized by IN Chemnitz, CLUG, computing centre and Faculty of Computer Science of Chemnitz University of Technology and many volunteers. Pick up your schedule and make a big mark around March 17 and 18. You won't regret it.

Updated TCP Proposals and FreeBSD

2012-02-05T00:05:42Z

There are a number of proposals for improving TCP performance coming out of Google that have some implications for FreeBSD. These proposals have taken the form of a group of IETF proposals, RFCs, patches to the Linux kernel, and research publications. A nice summary of the different initiatives is available from Lets Make TCP Faster on the Google Code Blog.

TCP Fast Open by Radhakrishnan, Cheng, Chu, Jain, and Raghavan is based on the observation that modern web services are dominated by TCP flows so short that they terminate a few round trips after handshaking. This means that the 3-way TCP handshake is a signiï¬?cant source of latency for such ï¬‚ows, and they describe a new mechanism for secure data exchange during the initial handshake to reduce some of the round-trip network transmission and associated latency for such short TCP transfers. This work shares many goals and challenges with T/TCP, which was previously in FreeBSD but suffered from some security vulnerabilities.

David Malone posted some thoughts on my Google+ post about how FreeBSD could implement the various changes. Maybe we could have some Summer of Code students work in this area this summer?

Working on Xorg Stuff!

2012-02-05T07:48:22Z

Hiho…

Well I know I haven’t been writing for a long time but there are always reasons behind it . Lately I have been busy with my job and personal life, but anyway I’m still alive and I have started working on FreeBSD since a while.

As stated in the subject, why I’m writing today is to talk about FreeBSD Xorg stuff. Personally I have stopped working on it for a long time. The main reason was that we are still stuck on some problems like missing KMS/GEM support, though since a while there is some progress that can be seen. Also kwm@ and eadler@ jumped into the Xorg team and did a lot of good work in the last few months.

As a result, Xorg gets 2 layers of framework. What this means, users with newer GFX hardware will get the chance to use newer Xorg server and drivers. The team has decided to create a new flag called WITH_NEW_XORG that users have to include in /etc/make.conf. This was mainly done for the intel KMS work being done. It should probably work for other chips. Unfortunately, the intel KMS driver will only work on FreeBSD 9-stable or 10-CURRENT users. Older version of FreeBSD will not be supported. Intel users will need to patch their src manually with Kib’s KMS kernel patch to get the newer chips to work. We have libGL and Mesa patches in our xorg-dev repo ready.

Here are some facts on what you will get with WITH_NEW_XORG:

libdrm 2.4.30 (including KMS support)
mesa 7.11.2
xorg-server 1.10.4
a lot of new Graphic Drivers.

After this is done and committed we going to work on Mesa 8.0 and X server 1.12. The reason we haven’t done this yet is because they are in RC stage and x server 1.11 and above break the nvidia driver. We will call for a testing soon with the full instruction on what you will have to do. So keep your eyes open..

So long…

PS: follow me on Twitter here.

What you should know about SSH

2012-02-03T14:38:56Z

Michael W. Lucas published his new book â€œSSH Masteryâ€? (no link to an online store, get it from your preferred online or offline one in your part of the world).

Do you think you know a lot about SSH? I thought I did when Michael searched technical proof-readers for this book. I offered to have a look at his work in progress and he gently accepted (while I do not get money for this, I am one of the persons he thanks forÂ the technical review in the beginning, so I am involved somehow and as such you should take the following with a grain of salt).

I already had user restrictions in place before the review, but now I narrowed down some restrictions based upon some conditionals. I already used SSH tunnels for various things before (where legally applicable), but I learned some additional VPN techniques with SSH. I already used multiple ssh-keys for various things, but Michael provides some interesting ways of handling a large-volume of ssh-keys over multiple machines. â€¦ I really hope that my review was as valuable for Michael, as it was for me to do the review.

He ends the book with â€œYou now know more about SSH, OpenSSH and Putty than the vast majority of IT professionals! Congratulationsâ€?, and this is true, and all that in his writing style where you can come with a problem, read about it, and leave with a solution (normally with a little bit of entertainment in between).

I know a lot of people which work daily with SSH, and they know only a small part of what is presented in this book. In my opinion this book is a must-have for every System/Database/Application/Whatever Administrator in charge of something on an UNIX-like system, and even â€œnormal usersâ€? of SSH (no matter if they use PuTTY, or a ssh command line program on an UNIX-like system (most probably it will be OpenSSH or a clone of it)) will get some helpful information from this book.

I can only recommend it.

Static DTrace probes for the linuxulator updated

2012-02-02T13:56:09Z

I got a little bit of time to update my 3 year old work of adding static DTrace probes to the linuxulator.

The changes are not in HEAD, but in my linuxulator-dtrace branch. The revision to have a look at is r230910. Included are some DTrace scripts:

script to check internal locks
script to trace futexes
script to generate stats for DTracified linuxulator parts
script to check for errors:
- emulation errors (unsupported stuff, unknown stuff, â€¦)
- kernel errors (resource shortage, â€¦)
- programming errors (errors which can happen if someone made a mistake, but should not happen)

The programming-error checks give hints about userland programming errors respectively a hint about the reason of error return values due to resource shortage or maybe a wrong combination of parameters. An example error message for this case is â€œApplication %s issued a sysctl which failed the length restrictions.nThe length passed is %d, the min length supported is 1 and the max length supported is %d.nâ€?.

The stats-script (tailored specially to the linuxulator, but this can easily be extended to the rest of the kernel) can report about:

number of calls to a kernel function per executable binary (not per PID!): allows to see where an optimization would be beneficial for a given application
graph of CPU time spend in kernel functions per executable binary: together with the number of calls to this function this allows to determine if a kernel optimization would be beneficial / is possible for a given application
graph of longest running (CPU-time!) kernel function in total
timing statistics for the emul_lock
graph of longest held (CPU-time!) locks

Unfortunately this can not be committed to HEAD as-is. The DTrace SDT provider can not handle probes which are added to the kernel after the SDT provider is already loaded. This means that you either have to compile the linuxulator statically into the kernel, or you have to load the SDT kernel module after the linuxulator module is loaded. If you do not respect this, you get a kernel panic on first access of one of the providers in the linuxulator (AFAIR this includes listing the probes available in the kernel).

New FreeBSD Forums box has been Shipped!

2012-01-31T21:01:34Z

I have just shipped the new FreeBSD Forums box. It will be much nicer to have a more powerful box and lots more RAM to play with. Maybe even let us implement things like Varnish finally!

FOSDEM 2012

2012-01-31T16:03:17Z

In a few days, I’ll be heading to the FOSDEM conference in Brussels again this year. On Saturday, you’ll most likely find me around the FreeBSD booth representing the FreeBSD Foundation, so if you’re there drop by to say hi, discuss the Foundation’s work, pick up a Foundation flyer, check out the swag, or make a donation. On Sunday, I’ll be in the BSD DevRoom where there will be some interesting presentations and discussions. Remember, FOSDEM is free to attend. Hope to see you there!

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Foundation at FOSDEM

2012-01-31T13:51:08Z

Erwin Lansing from the Foundation will be at FOSDEM, in Brussels, Belgium (February 4-5). He'll have some cool swag and can accept donations to the Foundation. You can find him hanging out at the FreeBSD booth in the expo area on Saturday and in the BSD Devroom on Sunday.

Interview with Deb Goodkin

2012-01-30T14:00:07Z

Episode 211 of bsdtalk has an interview with Deb Goodkin, Director of Operations for the FreeBSD Foundation. The interview is available as an mp3 or as an ogg.

bsdtalk211 – The FreeBSD Foundation with Deb Goodkin

2012-01-29T17:30:35Z

Interview with Deb Goodkin, Director of Operations for the FreeBSD Foundation.

The most recent newsletter, which talks about what the foundation did the last half of last year.

http://www.freebsdfoundation.org/press/2011Dec-newsletter.shtml#Letter

Their blog:

http://freebsdfoundation.blogspot.com/

Facebook:

https://www.facebook.com/FreeBSDFoundation

Lastly, but probably most importantly, people can donate here:

http://www.freebsdfoundation.org/donate/

File Info: 24Min, 12MB.

Ogg Link:
http://cisx1.uma.maine.edu/~wbackman/bsdtalk/bsdtalk211.ogg