Em Mon, Aug 20, 2007 at 10:22:40AM +1200, Ian McDonald escreveu: > On 8/20/07, Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx> wrote: > > Em Mon, Aug 20, 2007 at 08:53:15AM +1200, Ian McDonald escreveu: > > > On 8/20/07, Shahiduzzaman <shahid21st@xxxxxxxxx> wrote: > > > > Hi all, > > > > > > > > This may be a redundant or very naive question - sorry in advance for > > > > that. Can anybody tell me, whether the current Linux kernel DCCP > > > > implementation is done in a fashion like TCP pluggable congestion > > > > avoidance modules infrastructure (http://lwn.net/Articles/128681/) ? > > > > > > The short answer is yes and no! > > > > I think the answer is just "yes" > > > > The CCID infrastructure in the Linux kernel is done in a fashion like > > the TCP pluggable congestion avoidances modules infrastructure. One can > > write a new CCID and load, making it available for userspace programs to > > use without changing a line of code in what is already in the kernel. > > > > > No that the in-tree version does not support it. > > > > The question was if it was done "in a fashion like", not "exactly as". I > > may be confused with your answer as english is not my first language tho > > :-) > > > > I think my answer may have been confusing then... > > To clarify the CCID code is modular in that you don't need to write > the code from the ground up for a new CCID. It has callback functions > for implementing various protocol requirements. > > The part where it is not modular (in the tree anywhere) is if you want > to change just the very small part of how the congestion control is > done for any particular CCID. That needs improvements, yes, but even in this area we have separated a good number of routines in the tfrc library: [acme@mica net-2.6.24]$ l net/dccp/ccids/lib/ total 64 drwxr-xr-x 2 acme acme 4096 Aug 19 19:25 ./ drwxr-xr-x 3 acme acme 4096 Aug 19 19:26 ../ -rw-r--r-- 1 acme acme 7391 Aug 19 19:25 loss_interval.c -rw-r--r-- 1 acme acme 1019 Aug 19 19:25 loss_interval.h -rw-r--r-- 1 acme acme 119 Aug 19 19:25 Makefile -rw-r--r-- 1 acme acme 7806 Aug 19 19:25 packet_history.c -rw-r--r-- 1 acme acme 5853 Aug 19 19:25 packet_history.h -rw-r--r-- 1 acme acme 18708 Aug 19 19:25 tfrc_equation.c -rw-r--r-- 1 acme acme 1171 Aug 19 19:25 tfrc.h [acme@mica net-2.6.24]$ > I hope this clarifies a little. I get confused even though English is > my first language! Yes, it clarifies, and the discussion should provide the information that Shahiduzzaman is looking for. Ok, back to preparing a batch of patches for upstream submission, in my glacial pace, but hey, global warming will eventually reach my feets! :-) - Arnaldo
