Re: dead nfs mount blocks opening other folders

[Laszlo Kovacs <Laszlo Kovacs Sun COM>]

Alexander Larsson wrote:
> On Wed, 2004-12-15 at 11:58 +0000, Laszlo Kovacs wrote:
>
> > Alexander Larsson wrote:
>
>
> > > Is this really the problem? Are you sure the file being in a queue
> > > blocks other items in that queue from running? It seems to me that all
> > > items in a queue are started in parallel, and the problem seems to be
> > > that if the /brokennfsmount file sticks in one queue, the lower prio
> > > queues get no cycles at all.
> >
> > If you look at the loops in start_or_stop_io() you can see that if there 
> > is an element in a list and that element needs work done then that 
> > element will be processed and the rest of the list will be ignored for 
> > this cycle (there is a "return" statement there). So as long as the 
> > element is in the queue it blocks the rest of the list to be looked at.
>
>
> Ah, I see. I missed the return statement.
>    
>
> > > I'm not sure what a good solution is here. The blocking was done on
> > > purpose so that reading the high priority data from files wasn't
> > > hampered by reading low-prio data. Maybe we can allow a few items in the
> > > high prio queue when we start the low-prio one? Its not really a
> > > solution though... Maybe we can start the low prio queue when all items
> > > on the high prio queue has run for some minimal amount of time?
> >
> > What I had in mind is a mechanism where we mark an element as being 
> > processed when it is processed and if they are marked  when we get to 
> > the queue again then we move to the next one. Of course there is a lot 
> > of code here so a lot of care needs to be taken to fix it properly.
>
>
> I'm not sure what you mean. Say we get the first item in the high prio
> queue, and that item is already being processes (directory->details-
>
> > get_info_in_progress != NULL). What do you want to do in this case?

Skip it (in the "while" loop) and move to the next one? They are all 
async anyway. We need to make sure that all the other code that works 
with the lists as well still works with whatever changes are made.

I think this needs some careful examination to actually propose a fix 
(patch).

When I looked through this code my feeling was it was overly complicated 
and could use some simplification:-)

Laszlo

> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>  Alexander Larsson                                            Red Hat, Inc 
>                    alexl redhat com    alla lysator liu se 
> He's a notorious Republican farmboy with a winning smile and a way with the 
> ladies. She's a brilliant tomboy schoolgirl fleeing from a Satanic cult. They 
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