[dvblast-devel] [patch] make DVR_BUFFER_SIZE configurable

[Stas Sergeev]

28.10.2013 13:44, Marian Ďurkovič пишет:
>   DVR_BUFFER_SIZE was increased due to some device drivers, which
> suspend dataflow for as long as 500 msec (!) when querying the frontend
> status. Please don't decrease DVR_BUFFER_SIZE, it's simply an allocated
> amount of memory which doesn't have any negative effect on delay etc.
Hi, you can feel free to ignore the second patch then, and
apply only the one that makes it configurable. Then there is no
side effect.

However, I really disagree that it doesn't have any negative
effect. On embedded systems, allocating 8Mb of the unswappable
kernel memory just for the buffers, is a very big penalty.
Actually, for me it just triggers the OOM.
So I would still suggest making dvblast polite by default, and
increase the buffer with the command-line option for those
who need it. If you disagree, just ignore the second patch of mine.

Also, could you please clarify this:
> suspend dataflow for as long as 500 msec (!) when querying the frontend
> status.
Do you mean that _userspace_ is suspended while querying the frontend?
In this case you can just do that in a separate thread, no?

Why I choose to try dvblast, is because of this statement in its README:
---
It is very lightweight and
stable, designed for 24/7 operation.
---
So far it appears to be extremely heavyweight though.
I'd like to contribute into making it actually as advertised. :)