Re: [PATCH] fix IO hangs

[Nick Piggin]

Martin Schlemmer wrote:

> On Fri, 2003-09-05 at 19:04, Jens Axboe wrote:
>
> > On Fri, Sep 05 2003, Jens Axboe wrote:
> >
> > > > Jens, if insert_here is dead, there is no point to passing back a hint
> > > > because it can't get back to the elevator anyway.
> > > >
> > > > I'd very much like to kill insert_here and be done with it. If another
> > > > io scheduler comes along with a good use for it then the writers can
> > > > come up with an elegant solution ;) Hey, if they know a NO_MERGE return
> > > > means an insert will soon happen under the same lock, they could keep
> > > > it cached privately.
> > > Agree, lets just kill it off.
> > Here's the patch that kills it and its associated logic off completely.
> > Nick, I'm not too sure what the logic was for stopping anticipation in
> > as_insert_request() (the insert_here tests were somewhat convoluted :),
> > I've added what I think makes most sense: stop anticipating if someone
> > puts a request at the head of the dispatch list.
> >
> > It also makes the *_insert_request strategies much easier to follow,
> > imo.
>
> Hmm, do not know if its just me, but I just got two processes (cp's)
> in D state.  They did complete though, but throughput was not good.
> Any tips on getting it debugged ?

If they complete at all, then its very unlikely for them to be slowed
down (AS can do this a bit though). If you could get a comparison with
my patch that started the problems backed out it might tell me
something. Thanks.


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/