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From: Paul Emmerich <emmericp@net.in.tum.de>
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To: Stephen Hemminger <stephen@networkplumber.org>
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Subject: Re: [dpdk-dev] Polling too often at lower packet rates?
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Paul Emmerich <emmericp@net.in.tum.de> wrote:

> Stephen Hemminger <stephen@networkplumber.org> wrote:
>=20
>> Your excess polling consumes PCI bandwidth which is a fixed resource.
>=20
> I doubt that this is the problem for three reasons:
>=20

4th: polling should not cause a PCIe access as all the required =
information is written
to memory by the NIC [1].

I only noticed that after I tried to measure the PCIe bandwidth caused =
by polling an X540
NIC... the result was 0 MBit/s ;)


Paul

[1] 82599 and X540 data sheets, Table 1-9