On Sun, Aug 23, 2015 at 2:17 PM, Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx> wrote: > The entire logic that represent graph links were developed on a > time where there were no needs to dynamic remove links. So, > although links are created/removed one by one via some > functions, they're stored as an array inside the entity struct. > > As the array may grow, there's a logic inside the code that > checks if the amount of space is not enough to store > the needed links. If it isn't the core uses krealloc() > to change the size of the link, with is bad, as it > leaves the memory fragmented. > > So, convert links into a list. > > Also, currently, both source and sink entities need the link > at the graph traversal logic inside media_entity. So there's > a logic duplicating all links. That makes it to spend > twice the memory needed. This is not a big deal for today's > usage, where the number of links are not big. > > Yet, if during the MC workshop discussions, it was said that > IIO graphs could have up to 4,000 entities. So, we may > want to remove the duplication on some future. The problem > is that it would require a separate linked list to store > the backlinks inside the entity, or to use a more complex > algorithm to do graph backlink traversal, with is something > that the current graph traversal inside the core can't cope > with. So, let's postpone a such change if/when it is actually > needed. > > Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx> > I think it makes sense to add remove support in phase2 after the patches 1-15 in this series that add the graph object and the API changes that go with it through some use-cases before adding support for remove. That way we have confidence in the patch set 1-15 and then we can build on top with solid foundation. thanks, -- Shuah -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
