Re: fairsched + O(1) process scheduler

Robert Love (rml@tech9.net)
02 Apr 2003 17:10:27 -0500


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.

> 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.

Robert Love

-
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/