On Fri, 12 Jan 2007, YAMAMOTO Takashi wrote:

> unless anyone objects, i'll introduce something like callout(9)
> but its callback function is invoked in a thread context.  (see a.diff)
> i want to use it to schedule vmem rehashing.  (see b.diff)
>
> we probably will re-consider it when/if we make softclock be handled by
> the interrupt thread.

I don't have any grave objection, but did you consider adding this
capability to the callout(9) API directly?

I'm thinking something like:

	callout_init(&c);
	callout_setwork(&c, func, arg);
	callout_schedule(&c, timeout);

would be simpler? In usage, it would cost checking a flag for each
callout:

	if (c->flags & CALLOUT_THREAD) {
		/* schedule thread */
	} else {
		/* call function */
	}

.. probably not too expensive?

regards,
iain