Long Li 58a63729c9 net: mana: Fix doorbell out of order violation and avoid unnecessary doorbell rings ... After napi_complete_done() is called when NAPI is polling in the current process context, another NAPI may be scheduled and start running in softirq on another CPU and may ring the doorbell before the current CPU does. When combined with unnecessary rings when there is no need to arm the CQ, it triggers error paths in the hardware. This patch fixes this by calling napi_complete_done() after doorbell rings. It limits the number of unnecessary rings when there is no need to arm. MANA hardware specifies that there must be one doorbell ring every 8 CQ wraparounds. This driver guarantees one doorbell ring as soon as the number of consumed CQEs exceeds 4 CQ wraparounds. In practical workloads, the 4 CQ wraparounds proves to be big enough that it rarely exceeds this limit before all the napi weight is consumed. To implement this, add a per-CQ counter cq->work_done_since_doorbell, and make sure the CQ is armed as soon as passing 4 wraparounds of the CQ. Cc: stable@vger.kernel.org Fixes: e1b5683ff6 ("net: mana: Move NAPI from EQ to CQ") Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Long Li <longli@microsoft.com> Link: https://patch.msgid.link/1723219138-29887-1-git-send-email-longli@linuxonhyperv.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>		2024-08-13 13:09:54 +02:00
..
gdma.h	RDMA v6.11 merge window	2024-07-19 09:51:33 -07:00
hw_channel.h	net: mana: Annotate struct hwc_dma_buf with __counted_by	2023-10-02 11:24:54 -07:00
mana_auxiliary.h	net: mana: Move header files to a common location	2022-11-10 07:57:26 +02:00
mana.h	net: mana: Fix doorbell out of order violation and avoid unnecessary doorbell rings	2024-08-13 13:09:54 +02:00
shm_channel.h	net: mana: Move header files to a common location	2022-11-10 07:57:26 +02:00