On 11 Nov 2021, at 11:31, Randall Stewart <r...@freebsd.org> wrote: > > The branch main has been updated by rrs: > > URL: > https://cgit.FreeBSD.org/src/commit/?id=b8d60729deefa0bd13e6a395fcab4928e6e10445 > > commit b8d60729deefa0bd13e6a395fcab4928e6e10445 > Author: Randall Stewart <r...@freebsd.org> > AuthorDate: 2021-11-11 11:28:18 +0000 > Commit: Randall Stewart <r...@freebsd.org> > CommitDate: 2021-11-11 11:28:18 +0000 > > tcp: Congestion control cleanup. > > NOTE: HEADS UP read the note below if your kernel config is not including > GENERIC!! > > This patch does a bit of cleanup on TCP congestion control modules. There > were some rather > interesting surprises that one could get i.e. where you use a socket > option to change > from one CC (say cc_cubic) to another CC (say cc_vegas) and you could in > theory get > a memory failure and end up on cc_newreno. This is not what one would > expect. The > new code fixes this by requiring a cc_data_sz() function so we can malloc > with M_WAITOK > and pass in to the init function preallocated memory. The CC init is > expected in this > case *not* to fail but if it does and a module does break the > "no fail with memory given" contract we do fall back to the CC that was in > place at the time. > > This also fixes up a set of common newreno utilities that can be shared > amongst other > CC modules instead of the other CC modules reaching into newreno and > executing > what they think is a "common and understood" function. Lets put these > functions in > cc.c and that way we have a common place that is easily findable by future > developers or > bug fixers. This also allows newreno to evolve and grow support for its > features i.e. ABE > and HYSTART++ without having to dance through hoops for other CC modules, > instead > both newreno and the other modules just call into the common functions if > they desire > that behavior or roll there own if that makes more sense. > > Note: This commit changes the kernel configuration!! If you are not using > GENERIC in > some form you must add a CC module option (one of CC_NEWRENO, CC_VEGAS, > CC_CUBIC, > CC_CDG, CC_CHD, CC_DCTCP, CC_HTCP, CC_HD). You can have more than one > defined > as well if you desire. Note that if you create a kernel configuration that > does not > define a congestion control module and includes INET or INET6 the kernel > compile will > break. Also you need to define a default, generic adds 'options > CC_DEFAULT=\"newreno\" > but you can specify any string that represents the name of the CC module > (same names > that show up in the CC module list under net.inet.tcp.cc). If you fail to > add the > options CC_DEFAULT in your kernel configuration the kernel build will also > break.
Not doing so breaks tinderbox, as well as configs not hooks up to tinderbox. I don’t think this is acceptable. Jess
