On 21/06/2024 9:56, Kurt Kanzenbach wrote:
When running the igc with XDP/ZC in busy polling mode with deferral of hard
interrupts, interrupts still happen from time to time. That is caused by
the igc task watchdog which triggers Rx interrupts periodically.
That mechanism has been introduced to overcome skb/memory allocation
failures [1]. So the Rx clean functions stop processing the Rx ring in case
of such failure. The task watchdog triggers Rx interrupts periodically in
the hope that memory became available in the mean time.
The current behavior is undesirable for real time applications, because the
driver induced Rx interrupts trigger also the softirq processing. However,
all real time packets should be processed by the application which uses the
busy polling method.
Therefore, only trigger the Rx interrupts in case of real allocation
failures. Introduce a new flag for signaling that condition.
[1] -
https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=3be507547e6177e5c808544bd6a2efa2c7f1d436
Reviewed-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Vinicius Costa Gomes <[email protected]>
Acked-by: Maciej Fijalkowski <[email protected]>
Signed-off-by: Kurt Kanzenbach <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
---
Changes in v2:
- Index Rx rings correctly
- Link to v1:
https://lore.kernel.org/r/[email protected]
---
drivers/net/ethernet/intel/igc/igc.h | 1 +
drivers/net/ethernet/intel/igc/igc_main.c | 30 ++++++++++++++++++++++++++----
2 files changed, 27 insertions(+), 4 deletions(-)
Tested-by: Mor Bar-Gabay <[email protected]>
