Messages in this thread | | | Date | Tue, 6 Aug 2002 13:05:48 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH] 2.5.30 IDE 113 |
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On Tue, Aug 06 2002, Marcin Dalecki wrote: > Uz.ytkownik Jens Axboe napisa?: > >On Tue, Aug 06 2002, Marcin Dalecki wrote: > > > >>Uz.ytkownik Jens Axboe napisa?: > >> > >>>On Tue, Aug 06 2002, Marcin Dalecki wrote: > >>> > >>> > >>>>device not per channel! If q->request_fn would properly return the > >>>>error count instead of void, we could even get rid ot the > >>>>checking for rq->errors after finishment... But well that's > >>>>entierly different story. > >>> > >>> > >>>That's nonsense! What exactly would you return from a request_fn after > >>>having queued, eg, 20 commands? Error count is per request, anything > >>>else would be stupid. > >> > >>Returning the error count in the case q->request_fn is called for > >>a self submitted request like for example REQ_SPECIAL would be handy and > >>well defined. For the cumulative case it would of course make sense to > >>return the cumulative error count. Tough not very meaningfull, it would > >>indicate the occurrence of the error very fine. > > > > > >It's much nicer to maintain a sane API that doesn't depend on stuff like > >the above. Cumulative error count, come on, you can't possibly be > >serious?! > > Hey don't get me wrong - I *do not* suggest adding it becouse I don't > think we are going to change the "eat as many as possible requests" > instead of "eat one request" semantics of the q->reuqest_fn(). > OK?
You look from the IDE perspective, I look from the interface perspective. There's is no "eat one request" semantic of request_fn(), in fact there's just the opposite. If you quit after having just consumed one request, you must make sure to invoke request_fn _yourself_ later on -- or use the recent blk_start/stop_queue helpers.
-- Jens Axboe
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