Re: getiobuf(x, false) can sleep ?

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Fri, Apr 02, 2010 at 01:01:12PM +0000, Andrew Doran wrote:
> > - that buffer queue manipulations are done at splbio() with the
> >   kernel_lock held in dkstart() and dkstrategy():
> >       KASSERT(curcpu()->ci_biglock_count > 0);
> >       KASSERT(curcpu()->ci_ilevel >= IPL_BIO);
> >       KASSERT(curlwp->l_blcnt > 0); 
> > - that the buffer doesn't change under us in dkstart():
> >     KASSERT(BUFQ_GET(sc->sc_bufq) == bp);
> 
> Should this not be bufq_peek()?

No, the bufq_peek() has been done earlier, this is where bp comes from.
At this point we really want to dequeue the buffer (because we know we can
handle it); I just changed
        BUFQ_GET(sc->sc_bufq);
to
        KASSERT(BUFQ_GET(sc->sc_bufq) == bp);

> 
> Hmm, it shouldn't be doing dkiodone -> dkstart -> VOP_STRATEGY.
> VOP_STRATEGY should be called with process context (kthread, user).
> Anyhow that's unlikely to fix your problem.

dkiodone() is always called from thread or software interrupt context, isn't
that enough ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--