Byte queue limits (BQL) are an important step in reducing 'bufferbloat'
and network latency on Linux. The feature was introduced in Linux 3.3
and has had a few bug fixes since then; I think it can be considered
stable now. It requires specific support in drivers and is then
unconditionally enabled for them. It provides some tuning parameters,
but should not normally require these to be changed.
I have prepared a backport of this to Linux 3.2 that I would like to
include in wheezy, but I ran out of time to do that before the freeze.
Since BQL is a new feature, it would not normally be allowed to make
such a change now. However, it may also be considered an important fix
for performance problems (high network latency). Therefore I am
requesting a freeze exception in category 5, "pre-approved fixes". I
believe it can be easily backed-out in case it causes regressions.
BQL requires an ABI change, but so do some of the fixes in Linux 3.2.25,
so the next upload will have an ABI bump in any case.
Experience is directly proportional to the value of equipment destroyed.
- Carolyn Scheppner