[dpdk-dev] Weird 2 KB MBUF data room requirement
Morten Brørup
mb at smartsharesystems.com
Fri Jul 10 10:21:40 CEST 2020
Dear Ethernet PMD developers,
According to rte_mbuf_core.h, RTE_MBUF_DEFAULT_DATAROOM is 2048 bytes because some NICs need at least 2 KB buffer to receive standard Ethernet frames without splitting them into multiple segments.
This is a serious waste of memory, considering that standard Ethernet frames are max 1518 bytes.
How wide spread is this limitation... is it common or a rare exception?
Where is it documented which NICs suffer from this limitation?
Do any Intel NICs suffer from this limitation?
NB: We are targeting an MBUF total size (incl. memzone element overhead) of 2^N, and this limitation would increase our MBUF total size to 4 KB.
Med venlig hilsen / kind regards
- Morten Brørup
More information about the dev
mailing list