| Message ID | 20241009175509.31753-2-jdamato@fastly.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 25118cce6627ecceabd29d6795d7af16729a35dd |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | tg3: Link IRQs, NAPIs, and queues | expand |
On Wed, Oct 9, 2024 at 10:55 AM Joe Damato <jdamato@fastly.com> wrote: > > Link IRQs to NAPI instances with netif_napi_set_irq. This information > can be queried with the netdev-genl API. > > Signed-off-by: Joe Damato <jdamato@fastly.com> > Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com> Thanks. Reviewed-by: Michael Chan <michael.chan@broadcom.com>
diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index 378815917741..6564072b47ba 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -7413,9 +7413,11 @@ static void tg3_napi_init(struct tg3 *tp) { int i; - netif_napi_add(tp->dev, &tp->napi[0].napi, tg3_poll); - for (i = 1; i < tp->irq_cnt; i++) - netif_napi_add(tp->dev, &tp->napi[i].napi, tg3_poll_msix); + for (i = 0; i < tp->irq_cnt; i++) { + netif_napi_add(tp->dev, &tp->napi[i].napi, + i ? tg3_poll_msix : tg3_poll); + netif_napi_set_irq(&tp->napi[i].napi, tp->napi[i].irq_vec); + } } static void tg3_napi_fini(struct tg3 *tp)
Link IRQs to NAPI instances with netif_napi_set_irq. This information can be queried with the netdev-genl API. Begin by testing my tg3 device in its default state: 1 TX queue and 4 RX queues. Compare the output of /proc/interrupts for my tg3 device with the output of netdev-genl after applying this patch: $ cat /proc/interrupts | grep eth0 343: [...] eth0-tx-0 344: [...] eth0-rx-1 345: [...] eth0-rx-2 346: [...] eth0-rx-3 347: [...] eth0-rx-4 As you can see above, tg3 has named the IRQs such that there is a dedicated tx IRQ and 4 dedicated rx IRQs, for a total of 5 IRQs. $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \ --dump napi-get --json='{"ifindex": 2}' [{'id': 8197, 'ifindex': 2, 'irq': 347}, {'id': 8196, 'ifindex': 2, 'irq': 346}, {'id': 8195, 'ifindex': 2, 'irq': 345}, {'id': 8194, 'ifindex': 2, 'irq': 344}, {'id': 8193, 'ifindex': 2, 'irq': 343}] Netlink displays the same IRQs as above, noting that each is mapped to a unique NAPI instance. Now, reconfigure the NIC to have 4 TX queues and 4 RX queues: $ sudo ethtool -L eth0 rx 4 tx 4 $ sudo ethtool -l eth0 | tail -5 Current hardware settings: RX: 4 TX: 4 Other: n/a Combined: n/a Examine /proc/interrupts once again, noting that tg3 will now rename the IRQs to suggest that they are combined tx and rx without allocating additional IRQs, so the total IRQ count in /proc/interrupts is unchanged: 343: [...] eth0-0 344: [...] eth0-txrx-1 345: [...] eth0-txrx-2 346: [...] eth0-txrx-3 347: [...] eth0-txrx-4 Check the output from netlink again: $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \ --dump napi-get --json='{"ifindex": 2}' [{'id': 8973, 'ifindex': 2, 'irq': 347}, {'id': 8972, 'ifindex': 2, 'irq': 346}, {'id': 8971, 'ifindex': 2, 'irq': 345}, {'id': 8970, 'ifindex': 2, 'irq': 344}, {'id': 8969, 'ifindex': 2, 'irq': 343}] Signed-off-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com> --- v4: - Updated commit message rfcv3: - wrapped the netif_napi_add call to 80 characters drivers/net/ethernet/broadcom/tg3.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)