On 8/17/21 9:32 PM, Yunsheng Lin wrote:

This patchset adds the socket to netdev page frag recycling
support based on the busy polling and page pool infrastructure.

The profermance improve from 30Gbit to 41Gbit for one thread iperf
tcp flow, and the CPU usages decreases about 20% for four threads
iperf flow with 100Gb line speed in IOMMU strict mode.

The profermance improve about 2.5% for one thread iperf tcp flow
in IOMMU passthrough mode.

Details about the test setup? cpu model, mtu, any other relevant changes
/ settings.

How does that performance improvement compare with using the Tx ZC API?
At 1500 MTU I see a CPU drop on the Tx side from 80% to 20% with the ZC
API and ~10% increase in throughput. Bumping the MTU to 3300 and
performance with the ZC API is 2x the current model with 1/2 the cpu.

Epyc 7502, ConnectX-6, IOMMU off.

In short, it seems like improving the Tx ZC API is the better path
forward than per-socket page pools.