Commit aec5514d authored by Joe Damato's avatar Joe Damato Committed by Jakub Kicinski
Browse files

tg3: Link queues to NAPIs



Link queues to NAPIs using the netdev-genl API so this information is
queryable.

First, test with the default setting on my tg3 NIC at boot with 1 TX
queue:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump queue-get --json='{"ifindex": 2}'

[{'id': 0, 'ifindex': 2, 'napi-id': 8194, 'type': 'rx'},
 {'id': 1, 'ifindex': 2, 'napi-id': 8195, 'type': 'rx'},
 {'id': 2, 'ifindex': 2, 'napi-id': 8196, 'type': 'rx'},
 {'id': 3, 'ifindex': 2, 'napi-id': 8197, 'type': 'rx'},
 {'id': 0, 'ifindex': 2, 'napi-id': 8193, 'type': 'tx'}]

Now, adjust the number of TX queues to be 4 via ethtool:

$ sudo ethtool -L eth0 tx 4
$ sudo ethtool -l eth0 | tail -5
Current hardware settings:
RX:		4
TX:		4
Other:		n/a
Combined:	n/a

Despite "Combined: n/a" in the ethtool output, /proc/interrupts shows
the tg3 has renamed the IRQs to be combined:

343: [...] eth0-0
344: [...] eth0-txrx-1
345: [...] eth0-txrx-2
346: [...] eth0-txrx-3
347: [...] eth0-txrx-4

Now query this via netlink to ensure the queues are linked properly to
their NAPIs:

$ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
                         --dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8960, 'type': 'rx'},
 {'id': 1, 'ifindex': 2, 'napi-id': 8961, 'type': 'rx'},
 {'id': 2, 'ifindex': 2, 'napi-id': 8962, 'type': 'rx'},
 {'id': 3, 'ifindex': 2, 'napi-id': 8963, 'type': 'rx'},
 {'id': 0, 'ifindex': 2, 'napi-id': 8960, 'type': 'tx'},
 {'id': 1, 'ifindex': 2, 'napi-id': 8961, 'type': 'tx'},
 {'id': 2, 'ifindex': 2, 'napi-id': 8962, 'type': 'tx'},
 {'id': 3, 'ifindex': 2, 'napi-id': 8963, 'type': 'tx'}]

As you can see above, id 0 for both TX and RX share a NAPI, NAPI ID
8960, and so on for each queue index up to 3.

Signed-off-by: default avatarJoe Damato <jdamato@fastly.com>
Reviewed-by: default avatarMichael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20241009175509.31753-3-jdamato@fastly.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 25118cce
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