From 1919b39fc6eabb9a6f9a51706ff6d03865f5df29 Mon Sep 17 00:00:00 2001 From: Haiyang Zhang Date: Fri, 26 May 2023 08:38:57 -0700 Subject: net: mana: Fix perf regression: remove rx_cqes, tx_cqes counters The apc->eth_stats.rx_cqes is one per NIC (vport), and it's on the frequent and parallel code path of all queues. So, r/w into this single shared variable by many threads on different CPUs creates a lot caching and memory overhead, hence perf regression. And, it's not accurate due to the high volume concurrent r/w. For example, a workload is iperf with 128 threads, and with RPS enabled. We saw perf regression of 25% with the previous patch adding the counters. And this patch eliminates the regression. Since the error path of mana_poll_rx_cq() already has warnings, so keeping the counter and convert it to a per-queue variable is not necessary. So, just remove this counter from this high frequency code path. Also, remove the tx_cqes counter for the same reason. We have warnings & other counters for errors on that path, and don't need to count every normal cqe processing. Cc: stable@vger.kernel.org Fixes: bd7fc6e1957c ("net: mana: Add new MANA VF performance counters for easier troubleshooting") Signed-off-by: Haiyang Zhang Reviewed-by: Horatiu Vultur Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/1685115537-31675-1-git-send-email-haiyangz@microsoft.com Signed-off-by: Paolo Abeni --- include/net/mana/mana.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/net/mana') diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h index cd386aa7c7cc..9eef19972845 100644 --- a/include/net/mana/mana.h +++ b/include/net/mana/mana.h @@ -347,10 +347,8 @@ struct mana_tx_qp { struct mana_ethtool_stats { u64 stop_queue; u64 wake_queue; - u64 tx_cqes; u64 tx_cqe_err; u64 tx_cqe_unknown_type; - u64 rx_cqes; u64 rx_coalesced_err; u64 rx_cqe_unknown_type; }; -- cgit v1.2.3