[Intel-wired-lan] [PATCH intel-next] ice: Add support for persistent NAPI config

[Pucha, HimasekharX Reddy]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces at osuosl.org> On Behalf Of Joe Damato
> Sent: 22 October 2024 04:06
> To: netdev at vger.kernel.org
> Cc: Damato, Joe <jdamato at fastly.com>; Nguyen, Anthony L <anthony.l.nguyen at intel.com>; Kitszel, Przemyslaw <przemyslaw.kitszel at intel.com>; Andrew Lunn <andrew+netdev at lunn.ch>; David S. Miller <davem at davemloft.net>; Eric Dumazet <edumazet at google.com>; Jakub Kicinski <kuba at kernel.org>; Paolo Abeni <pabeni at redhat.com>; moderated list:INTEL ETHERNET DRIVERS <intel-wired-lan at lists.osuosl.org>; open list <linux-kernel at vger.kernel.org>
> Subject: [Intel-wired-lan] [PATCH intel-next] ice: Add support for persistent NAPI config
>
> Use netif_napi_add_config to assign persistent per-NAPI config when initializing NAPIs. This preserves NAPI config settings when queue counts are adjusted.
>
> Tested with an E810-2CQDA2 NIC.
>
> Begin by setting the queue count to 4:
>
> $ sudo ethtool -L eth4 combined 4
>
> Check the queue settings:
>
> $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
>                          --dump napi-get --json='{"ifindex": 4}'
> [{'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8452,
>   'ifindex': 4,
>   'irq': 2782},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8451,
>   'ifindex': 4,
>   'irq': 2781},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8450,
>   'ifindex': 4,
>   'irq': 2780},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8449,
>   'ifindex': 4,
>   'irq': 2779}]
>
> Now, set the queue with NAPI ID 8451 to have a gro-flush-timeout of
> 1111:
>
> $ sudo ./tools/net/ynl/cli.py \
>             --spec Documentation/netlink/specs/netdev.yaml \
>             --do napi-set --json='{"id": 8451, "gro-flush-timeout": 1111}'
> None
>
> Check that worked:
>
> $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
>                          --dump napi-get --json='{"ifindex": 4}'
> [{'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8452,
>   'ifindex': 4,
>   'irq': 2782},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 1111,
>   'id': 8451,
>   'ifindex': 4,
>   'irq': 2781},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8450,
>   'ifindex': 4,
>   'irq': 2780},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8449,
>   'ifindex': 4,
>   'irq': 2779}]
>
> Now reduce the queue count to 2, which would destroy the queue with NAPI ID 8451:
>
> $ sudo ethtool -L eth4 combined 2
>
> Check the queue settings, noting that NAPI ID 8451 is gone:
>
> $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
>                         --dump napi-get --json='{"ifindex": 4}'
> [{'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8450,
>   'ifindex': 4,
>   'irq': 2780},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8449,
>   'ifindex': 4,
>   'irq': 2779}]
>
> Now, increase the number of queues back to 4:
>
> $ sudo ethtool -L eth4 combined 4
>
> Dump the settings, expecting to see the same NAPI IDs as above and for NAPI ID 8451 to have its gro-flush-timeout set to 1111:
> 
> $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
>                          --dump napi-get --json='{"ifindex": 4}'
> [{'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8452,
>   'ifindex': 4,
>   'irq': 2782},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 1111,
>   'id': 8451,
>   'ifindex': 4,
>   'irq': 2781},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8450,
>   'ifindex': 4,
>   'irq': 2780},
>  {'defer-hard-irqs': 0,
>   'gro-flush-timeout': 0,
>   'id': 8449,
>   'ifindex': 4,
>   'irq': 2779}]
>
> Signed-off-by: Joe Damato <jdamato at fastly.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_base.c | 3 ++-  drivers/net/ethernet/intel/ice/ice_lib.c  | 6 ++++--
>  2 files changed, 6 insertions(+), 3 deletions(-)
>

Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha at intel.com> (A Contingent worker at Intel)