Use of contiguous physical memory in ixgbe driver

Navdeep Parhar np at
Tue May 6 17:21:14 UTC 2014

On 05/06/14 09:06, Alexander V. Chernikov wrote:
> Hello guys.
> (bootstrapping people involved in previous version of this topic, sorry
> for that)
> There were several problem descriptions/discussions on using 9k+ mbufs
> with current allocator in:
> if_em: kern/183381
> cxgbe:
> general one:

I changed cxgbe(4) in response to those discussions (see r263317 for
details; r263451 has the man page updates).  It still prefers large
clusters (if MTU is > 4K) by default but will happily fall back to the
4K zone if it encounters failures when allocating from the larger zones.
 I also added a knob that you can use to forbid cxgbe(4) from even
attempting to allocate from the large zones.

So the latest cxgbe(4) should be able to cope just fine at whatever MTU
even when the 9K, 16K zones are depleted.


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