Re: [Mvpmc-devel] reducing memory use in MythTV client

[Roger H. <ra...@wi...>]

Tom Metro wrote:
> ge...@ac... wrote:
>> Tom Metro wrote:
>>> Operations that trigger loading listing data are the ones most apt to 
>>> cause a slowdown, like deleting shows.
>> I suppose this means that you can play lots of recordings during those
>> periods in time where the backend is not recording anything, right?
> 
> Perhaps. Viewing recording is typically followed by deleting recordings, 
> so it's hard to say.
> 
> 
>>> In some cases the UI becomes very slow to respond...
>> So how long have these problems been around?  Are people just noticing
>> them now that they have accumulated many hundreds of recordings?  Or has
>> the behaviour of newer backends changed something?
> 
> I set up MythTV in November 2006 and used mvpmc as the front-end from 
> the start. By about February 2007 I started having problems with the UI 
> slowing down and was posting to the users list about it. Obviously at 
> that time the cause wasn't known, but you'll find a thread on the list 
> where Michael Drons was helping me debug the problem and we spent a 
> while chasing the red herring of Ethernet overrun errors.
> 
> As with Roger, I've been running pretty much the same back-end version 
> during this entire period. Just the usual maintenance upgrades.
> 
> It seems pretty clear that there is a correlation to the quantity of 
> recordings. If we had any serious doubts, this could be tested by 
> temporarily swapping the MythTV database for one that has most of the 
> recording records deleted.
> 
>   -Tom

Here is something interesting, I just upgraded to 0.21, everything
so far I have used seems to work ok.   And because of the message
below being ignored the bad delete behavior seems to have gone away.

Below is the message, it would appear that ignoring this message would
be the correct thing to do if mvpmc can identify that it actually did
the delete.

unknown mythtv BACKEND_MESSAGE 'RECORDING_LIST_CHANGE DELETE 1036 
2008-03-13T22:58:00'
MythTV unknown event (error?)

If another backend did the delete, it should probably do the refresh,
which it does not appear to be doing now since it is ignoring the message.

This so far seems to lessen memory issue, probably because before there
was the mvpmc deleting the entry and refreshing the menu, and then there
appeared to be second event updating the list on the delete and it appeared
to me that there was some bad interaction between the 2 updates happening at 
about the same time that was causing the memory issue with a large number of 
recordings.

                             Roger