Mel Gorman: Kernel Spanner

A large number of patches were merged in 3.6-rc1 to support activating a swapfile on NFS and improving the reliability of swapping over a network block device. While it has been possible to activate swap against an NBD device for a long time it was not exactly a great idea. Significant memory pressure would likely cause the machine to freeze requiring a reboot. I expect that this particular problem is in the past but if not, then sure I'll get cc'd on a bug report. This feature was something I pushed for a while as I knew there were a number of use cases that people cared about and it's something that was carried in SLES for quite a while as a result.

However, this blog entry was unexpected and it gave me a swelled head, particularly coming from someone like Wouter. That beer also sounds mighty tempting but thing is, he almost certainly does not remember this but we met before, somewhere between six and eight years ago drinking beer outside one of the buildings at FOSDEM. Not exactly sure when, it was a hell of a long time ago.He bought a few spares after a trip to a bar and gave me one but left before I had the chance to buy one back. This effectively broke the Round System and for some stupid reason I remembered it pretty much every time I read a post of his on Planet Debian. For now, assuming Wouter does not file any bug reports after 3.6 comes out then maybe I can just call us even and let it go

I've been out ill the last few days (and still am). As having a head full of goo made be dumber than the average stick that couldn't do more than an hour or two of useful work in a day, I decided to fire up nethack again to chew up a bit of the day. The only games I play are guitar hero variants, final fantasy anything and nethack which was the first game I played on the PS3. I hadn't played properly in months as the last time I almost made it which just sickened me. The one exception was a game a few weeks ago for a local competition that had a keg as a prize if someone ascended (no one did).

The game was mainly a grind but being dumb also made me patient. One major setback was cancelling the whole inventory including the Bell of Opening which needs charged to finish the game. This is dumb, don't do it. I had the Wizard of Yendor killed by the time I realized the artifact was a no-go and there was no means of charging or wishing left in the game as I had them cleared out or used already. In a somewhat disgruntled mood, I put the character in a situation where it was attacked by literally all the time to finish the game and call it a day. Fortunately for me, between the monsters summoned by having being negatively aligned with negative luck and the repeated monsters summoned by the Wizard, eventually a scroll of charging fell out for the first time in the game putting me back in action and levelled me up considerably in the process. After opening the sanctum I found another scroll which was enough to get a magic marker to bring my AC back to something respectable and stand up to two wizards (double trouble), the high priest of Moloch and various beasties at the same time without using wands of death as I had lost all instant-kill methods at that time. Was a real messy fight but eventually with the Amulet of Yendor in hand and after poking the Wizard a few more times in the eye, I got to the Astral planes. Visiting all three altars later and last night night I see the lovely message.

"In return for thy service, I grant thee the gift of Immortality!" You ascend to the status of Demigod...

Mel the Lord St:25 Dx:18 Co:18 In:16 Wi:18 Ch:18 Lawful
Astral Plane $:175 HP:441(441) Pw:141(141) AC:-23 Xp:30/100090501 T:99085 Satiated

Wooooo! This is the full dump file and now, it's time to jam yet more wonderful drugs into my head and clear it out!

I am just back online after being absent for two weeks. If you were trying to get in touch with me in that time and I am apparently ignoring mails, nudge me again because it is lost in the mess. The start of the absense was due to presenting a paper at ISMM 2008 in Tuscon, Arizona. The conference is fairly in-depth and was of significant interest despite many of the discussions are around managed languages and garbage collection which I do not focus on ordinarily. Luckily for me, attending next year will be relatively handy as it is due to be held in Dublin, Ireland.

Post conference, I drove to Portland, Oregan over the course of two weeks stopping off at various places along the way such as Vegas (a unique place), Bagdad (in Arizona, not the other one), Los Angeles and Yosemite park. I'm now parked up in Portland for the next 4 weeks so if anyone in the area wants to meet up that has met me in the past, drop a line and we'll make something happen.

This is the beginning of what I intend to be a semi-technical blog on what is happening with the Linux kernel with the virtual memory manager (VMM). At the time of writing, I work with IBMs Linux Technology Center out of a house in Limerick, Ireland. I guess the usual disclaimer is that on this blog, I speak on my own behalf and in no way represent IBM's position, strategies or whatever else occurs to you related to the company. While far from being the most influencial VMM developer in Linux, there is not a whole pile of information out there on what is happening and something is better than nothing. Most of the time, I work on improving large page support so I imagine many posts will deal with that subject. Depending on the mood, general activity and spare time, I'll blabber on about other subjects.