From: "Morten Brørup" <mb@smartsharesystems.com>
To: <dev@dpdk.org>
Cc: "Olivier Matz" <olivier.matz@6wind.com>
Subject: [dpdk-dev] Weird 2 KB MBUF data room requirement
Date: Fri, 10 Jul 2020 10:21:40 +0200 [thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35C61113@smartserver.smartshare.dk> (raw)
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
next reply other threads:[~2020-07-10 8:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-10 8:21 Morten Brørup [this message]
2020-07-10 10:26 ` Bruce Richardson
2020-07-10 12:58 ` Olivier Matz
2020-07-10 13:45 ` Morten Brørup
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