Re: Bottom halves.
Rogier Wolff (R.E.Wolff@BitWizard.nl)
Fri, 1 Oct 1999 17:05:18 +0200 (MEST)
B. James Phillippe wrote:
> On Fri, 1 Oct 1999, Rogier Wolff wrote:
>
> > While investigating I found that do_bottom_halves is one of the places
> > where interrupts have to wait a long time.
> >
> > The comment at the top states:
> >
> > * do_bottom_half() runs at normal kernel priority: all interrupts
> > * enabled. do_bottom_half() is atomic with respect to itself: a
> > * bottom_half handler need not be re-entrant.
> >
> > But then the code does:
> >
> > __sti();
> > run_bottom_halves();
> > __cli();
> >
> > Have the comments grown outdated with respect to the actual code?
>
> __sti() enables interrupts on the processor that it was executed on.
> __cli() disables them. You snipped the code that shows the reentrancy
> locking. I don't see the problem.
Right. Sorry, I just made a fool out of myself: I didn't glance long
enough at the sti/cli to see that they are the other way around as I'd
expected.
And now back to our regular program.... ;-)
Roger.
--
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