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Subject: rte_eth_stats_get seems slow
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Date: Fri, 25 Apr 2025 13:52:55 +0200
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Thread-Topic: rte_eth_stats_get seems slow
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From: =?iso-8859-1?Q?Morten_Br=F8rup?= <mb@smartsharesystems.com>
To: <bruce.richardson@intel.com>
Cc: "Ian Stokes" <ian.stokes@intel.com>,
	<dev@dpdk.org>
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Bruce,

rte_eth_stats_get() on Intel NICs seems slow to me.

E.g. getting the stats on a single port takes ~132 us (~451,000 CPU =
cycles) using the igb driver, and ~50 us using the i40e driver.

Referring to the igb driver source code [1], it's 44 calls to =
E1000_READ_REG(), so the math says that each one takes 3 us (~10,000 CPU =
cycles).

Is this expected behavior?

It adds up, e.g. it takes a full millisecond to fetch the stats from =
eight ports using the igb driver.

[1]: =
https://elixir.bootlin.com/dpdk/v24.11.1/source/drivers/net/e1000/igb_eth=
dev.c#L1724


Med venlig hilsen / Kind regards,
-Morten Br=F8rup