BMC on concurrency

Bryan Cantrill has just posted one of the more excellent blog posts I've seen this year -- he manages to put to words some of my heretofore unvoiced doubts about transactional memory. I'm a big fan of KISS, and both TM and multilevel threading seem to fail on that front.

fdc suspend/resume support

In another update, I've updated fdc (the floppy disk controller) so that it supports suspend/resume even if a floppy drive is present. There is one caveat though -- namely that the drive must be empty. Still, its far easier to pull a disk out of a drive (if you even have one -- most floppy drives these days probably see very little, if any, use), than to disconnect the drive entirely.

You can download the file from the device drivers download page (look for a file named fdc-2008-11-01.tar.gz). A webrev of the changes is also posted.

For the curious, the reason for the above caveat is best stated by the following explanation extracted from a comment in the code:

Bad, bad, bad things will happen if someone changes the disk in the drive while it is mounted and the system is suspended. We have no way to detect that. (Undetected filesystem corruption. Its akin to changing the boot disk while the system is suspended. Don't do it!)

So we refuse to suspend if there is media present in the drive. This limits some of the usability of suspend/resume, but it certainly avoids this potential filesytem corruption from pilot error. Given the decreasing popularity of floppy media, we don't see this as much of a limitation.

Anyway, I suspect these changes may have little value to laptops, but may help a lot of desktops. It certainly addresses the problem of SUSPEND for my Dell Precision M390.

Update: Thanks to Jürgen Keil's testing, we have found a bug, which I've fixed. The webrev and the binaries have been updated accordingly. Look for the 11-04 release instead.

iprb updated with suspend/resume & quiesce

I've updated iprb (Intel Pro/100 Ethernet driver) to support suspend/resume and quiesce (fast reboot). I've also made some other changes, such as updating to the latest microcode from Intel, fixing some potential races, and improving the internal implementation of the statistics routine.

I'd like folks to try it out on their Intel or AMD platforms. The tarball can be downloaded from here (look for iprb-2008-11-01.tar.gz).

I still want to get this open sourced, but I haven't got approval from the lawyers yet. But here are the binary bits in case anyone is waiting for them.

(I'm not planning on porting this driver to SPARC. There are too many places in the code that would have to be changed to use endian-safe calls to ddi_get, and I think there is probably very little demand for a SPARC version of the driver. If you are one of the people who do want SPARC support for iprb, please let me know.

Enjoy!

Boomer: Next Generation Audio for Solaris

I've posted draft inception materials for our PSARC case, 2008/318, for Boomer. Boomer is the code name for the effort to integrate a modern OSS-compatible API, and additional drivers, into Solaris.

PSARC inception review for this case is scheduled for November 5, 2008. Please check the ARC web page for call in details (any engineer in the community may dial in.) Be advised that the meeting is an engineering meeting, though. (PSARC provides engineering architectural review for projects.)

We have a working prototype for most of the bits we are ARC'ing at this point, and I expect to be opening up the source code tree, and binary test bits, in the coming weeks. Perhaps by Thanksgiving.

Sun position available in Austin

A new position in Austin, TX has opened in my group (onsite only). This is for a junior or mid-level administrator or QA type person -- great for someone who loves playing with new hardware, software, etc. No specific programming skills beyond every day scripting required (though perl and C would probably be useful.) Send replies back to me. (Full disclosure: I get a referral bonus for anyone I refer.)

Microsoft & NetBSD

Some folks might be interested in this. I used to hack on NetBSD at my previous job. I recently had an inquiry from a recruiter at Microsoft (don't worry Neal, I'm not going anywhere! :-) which I thought I'd share here.

Location: Redmond, WA
Client: Microsoft.
Job Description:

Seeking a talented NetBSD software developer interested in helping Danger (a subsidiary of Microsoft) ship the next generation of Danger’s Sidekick platform. Specifically, we’re looking for NetBSD developers interested in commercializing the NetBSD platform for an embedded mobile computing device, focusing on performance and optimization, bug fixing, and integration with Danger’s higher-level platform code, with an emphasis on kernel and driver support.

Qualifications:

- 8+ years of software development experience

- 8+ years experience with C

- Strong understanding of OS concepts (particularly with NetBSD) such as multi-threaded program design and synchronization, processes & memory protection, etc.

- Strong communication skills

- Strong understanding of the NetBSD/GNU software development process and embedded development & debugging techniques

- Deep understanding of NetBSD, including timers, RPC, TCP/IP, etc.

- Experience with ARM processors highly desirable

So, not Windows CE or some other Windows platform. Cool. Wonder when they'll start posting job offers for Solaris engineers? (Probably as soon as Solaris is useful for small embedded devices -- i.e. I wouldn't hold my breath. :-)

New Stuff in OpenSolaris 2008.11

OpenSolaris 2008.11 is coming soon. Build 101 is the stabilization build before it, and as usual, new features are excluded from this build. So we can say pretty certainly what features are in, and what are out.

While there are a lot of new features coming in this release, there are some in particular that I've been more involved with.

1. SDcard support. Numerous laptops can now use SDcard and MultiMediaCard media directly. A good way to know if you're laptop is one of them is to search for pciclass,0805 in the output of prtconf -vp. While it isn't completely conclusive (in particular some models from Texas Instruments are schizophrenic here), if you see this, there's an excellent chance it will work. I'd always like to hear feedback about this feature -- if your unit works, or doesn't work, let me know. (Also, of course, the Tadpole SPARCLE models are supported. )
2. AudioHD improvements. Notably, many more laptops will now have working audio. The audiohd driver is also updated to support Suspend/Resume.
3. Fast Reboot. I participated as a consultant. I'll also be updating (post OpenSolaris 2008.11) additional drivers to support this feature. The upshot of this project is that a healthy system can reboot much more quickly now.
4. Brussels (NIC Administration). I've participated in converting several drivers to Brussels, and in generally improving Brussels (I'm also the ARC sponsor for this work.) The upshot of this project is greatly improved manageability for network interfaces.
5. Suspend (S3) Support. I helped review the conversions of several drivers, and provided fixes for several NIC devices.
6. Bug Fixes. I've worked on a number of them, and of course, there are huge numbers of bugs that have been fixed in this release.

All said, I think OpenSolaris 2008.11 is going to be great -- I confess that I was skeptical about the earlier releases, but this release is shaping up to be really awesome.