Re: [patch] vmfixes-2.4.0-test9-B2

Jens Axboe
2000-09-25T14:18:54Z

On Mon, Sep 25 2000, Andrea Arcangeli wrote:
> > The sg problem was different. When sg queues a request, it invokes the
> > request_fn to handle it. But if the queue is currently plugged, the
> > scsi_request_fn will not do anything.
>
> That will explain it, yes. In the same way for correctness also those should
> be converted from request_fn to generic_unplug_device, right? (this

Yes, that would be the right fix. However, then we also need some
way of inserting requests in the queue and let it plug when appropriate.
The scsi layer currently "manually" does a list_add on the queue itself,
which doesn't look too healthy.

> will also avoid to recall spurious request_fn because the device is still
> in the tq_disk queue even when the I/O generated by the below request_fn
> completed)
>
> if (major >= COMPAQ_SMART2_MAJOR+0 && major <= COMPAQ_SMART2_MAJOR+7)
> (q->request_fn)(q);
> if (major >= DAC960_MAJOR+0 && major <= DAC960_MAJOR+7)
> (q->request_fn)(q);

AFAIR, Eric tried to talk to the Compaq folks (and Leonard too, I dunno)
about why they want this. What came of it, I don't know.

--
* Jens Axboe <axboe@suse.de>
* SuSE Labs