On Tue, Dec 02, 2014 at 12:52:51PM +0900, Masao Uebayashi wrote: > On Tue, Dec 2, 2014 at 5:32 AM, Thor Lancelot Simon <[email protected]> wrote: > > Try it! It's quite a mess, particularly around target and bus > > attach/detach. > > scsipi and wscons are the worst in that respect. > > (Who wants to be a hero?)
Dear Mr. Hero, I have a couple of NetBSD kernel projects every winter, to give me something to do during my commute (in the winter, I take the train; in the summer, I bike). The way I pick them is that I have to be able to restart the project every week or so, having forgotten where I was, and figure out what I was doing again in 20 minutes or less -- my commute is about 50 minutes. That way I can get at least 30 minutes of stuff done any day I don't have something else to do. I tried "devise locking scheme for SCSI code" as one of those projects for about a week last winter. Utterly hopeless. Perhaps someone more clever or dedicated can make some progress, but I would suggest it is the kind of work that will require several consecutive days and a lot of planning just to get started -- and hours of effort at a time, over several weeks to finish. My best guess using my OOMA Engineering Manager's Manual is that actually getting any meaningful concurrency in the SCSI code, for disks, is about 20 or 30 hours of work total. So if you are lucky enough to have 3 consecutive hours of spare time every day, 5 days a week, and you trust my guesswork, you can assume you are looking at somewhere between 1 and 2 weeks of hacking. I have a wide array of SCSI controllers and targets that would let you exercise many of the drivers. If you're serious about this, send me a project plan to indicate your interest and I will send them to you or provide access. -- Thor Lancelot Simon [email protected] "From the tooth paste you use in the morning to the salt on your evening meal, it's easy to take for granted the many products brought to us with explosives." - Institute of Manufacturers of Explosives, "Explosives Make It Possible"
