Messages in this thread | | | From | campbell@tirian ... | Date | Wed, 7 May 1997 18:52:57 +0200 | Subject | Re: Timer queues: Which one should I use... |
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> From: alan@lxorguk.ukuu.org.uk (Alan Cox) > Subject: Re: Timer queues: Which one should I use... > To: grant@knot.torque.net (Grant R. Guenther) > Date: Tue, 6 May 1997 23:30:30 +0100 (BST) > Cc: campbell@tirian.che.curtin.edu.au, linux-kernel@vger.rutgers.edu
> > David and others have observed that under heavy load a ZIP drive can > > cause systems to freeze. The ppa adapter doesn't generate an interrupt, > > Can you not get the thing to give you an interrupt does it not waggle paper > out or ack or anything useful ?
It waggles ack when the attached device (the disk) is selected which is not very useful since this is the only pin that will generate hardware interrupts.
> > so the driver must simulate interrupts using task queues. There are two > > basic choices: tq_scheduler and tq_timer. > > Or add_timer() a timer of your own.
Hmm... Can add_timer() do 1000 us call backs??
>> I've since switched to using tq_timer with more stable results but >> apparently there has been a performance drop. Any suggestions? > >Add it to both queues and take it off the other when it is called ?
Fine except for one minor problem, I can't find a routine to remove a request once it is on a task queue. Either that or I'm looking at a very old <linux/tqueue.h>.
David Campbell
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