Re: fairsched + O(1) process scheduler

From: Antonio Vargas (wind@cocodriloo.com)
Date: Wed Apr 02 2003 - 17:35:57 EST


On Wed, Apr 02, 2003 at 05:10:27PM -0500, Robert Love wrote:
> On Wed, 2003-04-02 at 17:07, Antonio Vargas wrote:
>
> > Hmmm, we had some way for executing code just after an interrupt,
> > but outside interrupt scope... was it a bottom half? Can you
> > point me to some place where it's done?
>
> Unfortunately uidhash_lock cannot be used from a bottom half either.
>
> You can push it into a work queue. See schedule_work() and the default
> events queue.

I'll take a look.

> > Ok, I did know m68k can do it, but wasn't sure about all other arches :)
>
> Yep. Everyone architecture I know of - and certainly all that Linux
> support - can do atomic read/writes to a word. Thinking about it, it
> would be odd if not (two writes to a single word interleaving?). There
> are places this assumption is used.
>
> Anything more complicated, of course, needs atomic operations or locks.

"word == basic unit of transfer from/to memory" on your reasoning, I suppose.

I'm coding this now, hope I can post a basic implementation.

Greets, Antonio.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Mon Apr 07 2003 - 22:00:17 EST