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From: fwefew 4t4tg <7532yahoo@gmail.com>
To: users@dpdk.org
Subject: DPDK and DMA
Date: Sun, 8 Jan 2023 16:05:55 -0500	[thread overview]
Message-ID: <CA+Tq66XLG0_crfX81-egmvuCjwTPC8QX_Db1PHaFryG_au667w@mail.gmail.com> (raw)

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Consider a valid DPDK TXQ with its mempool of rte_mbufs. Application code
will allocate a mbuf from the pool and prepare it with headers, data, and
so on.

When the mbuf(s) are enqueued to the NIC with rte_eth_tx_burst() does DPDK
DMA the memory into the NIC? Is this an optimization worth considering?

DPDK provides a DMA example here:
http://doc.dpdk.org/api/examples_2dma_2dmafwd_8c-example.html

Now, to be fair, ultimately whether or not DMA helps must be evidenced by a
benchmark. Still, is there any serious reason to make mempools and its
bufs DMA into and out of the NIC?

Any perspective here is appreciated.

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             reply	other threads:[~2023-01-08 21:06 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-08 21:05 fwefew 4t4tg [this message]
2023-01-11 11:26 ` Dmitry Kozlyuk
2023-01-11 18:05   ` fwefew 4t4tg
2023-01-11 18:54     ` Stephen Hemminger
2023-01-11 20:14     ` Dmitry Kozlyuk

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