From: "Morten Brørup" <mb@smartsharesystems.com>
To: "Olivier Matz" <olivier.matz@6wind.com>, <dev@dpdk.org>
Subject: mbuf headroom question
Date: Thu, 6 Jan 2022 10:29:11 +0100 [thread overview]
Message-ID: <98CBD80474FA8B44BF855DF32C47DC35D86DE0@smartserver.smartshare.dk> (raw)
Hi Olivier,
The data_room_size parameter description for the mbuf pool creation functions says:
"Size of data buffer in each mbuf, including RTE_PKTMBUF_HEADROOM."
Furthermore, both rte_mbuf_data_iova_default() and rte_mbuf_data_addr_default() simply add RTE_PKTMBUF_HEADROOM to the return value.
Based on the above, I would think that it is impossible for m->buf_len to be smaller than RTE_PKTMBUF_HEADROOM.
So why does rte_pktmbuf_reset_headroom() use RTE_MIN(m->buf_len, RTE_PKTMBUF_HEADROOM), instead of just RTE_PKTMBUF_HEADROOM? What am I missing here?
Med venlig hilsen / Kind regards,
-Morten Brørup
next reply other threads:[~2022-01-06 9:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-06 9:29 Morten Brørup [this message]
2022-01-06 9:48 ` Olivier Matz
2022-01-06 10:50 ` Morten Brørup
2022-01-06 12:41 ` Olivier Matz
2022-01-06 12:49 ` Morten Brørup
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