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The NetDIM library, currently leveraged by an array of NICs, delivers
excellent acceleration benefits. Nevertheless, NICs vary significantly
in their dim profile list prerequisites.
Specifically, virtio-net backends may present diverse sw or hw device
implementation, making a one-size-fits-all parameter list impractical.
On Alibaba Cloud, the virtio DPU's performance under the default DIM
profile falls short of expectations, partly due to a mismatch in
parameter configuration.
I also noticed that ice/idpf/ena and other NICs have customized
profilelist or placed some restrictions on dim capabilities.
Motivated by this, I tried adding new params for "ethtool -C" that
provides
a per-device control to modify and access a device's interrupt
parameters.
Usage
========
The target NIC is named ethx.
Assume that ethx only declares support for
ETHTOOL_COALESCE_RX_EQE_PROFILE
in ethtool_ops->supported_coalesce_params.
1. Query the currently customized list of the device
$ ethtool -c ethx
...
rx-eqe-profile:
{.usec = 1, .pkts = 256, .comps = 0,},
{.usec = 8, .pkts = 256, .comps = 0,},
{.usec = 64, .pkts = 256, .comps = 0,},
{.usec = 128, .pkts = 256, .comps = 0,},
{.usec = 256, .pkts = 256, .comps = 0,}
rx-cqe-profile: n/a
tx-eqe-profile: n/a
tx-cqe-profile: n/a
2. Tune
$ ethtool -C ethx rx-eqe-profile 1,1,0_2,2,0_3,3,0_4,4,0_5,5,0
