linux-kernel - Re: [PATCH V3,net] net: mana: Fix perf regression: remove rx_cqes, tx

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Message-Id: <168544142040.13918.458960316651183871.git-patchwork-notify@kernel.org>
Date:   Tue, 30 May 2023 10:10:20 +0000
From:   patchwork-bot+netdevbpf@...nel.org
To:     Haiyang Zhang <haiyangz@...rosoft.com>
Cc:     linux-hyperv@...r.kernel.org, netdev@...r.kernel.org,
        decui@...rosoft.com, kys@...rosoft.com, paulros@...rosoft.com,
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Subject: Re: [PATCH V3,net] net: mana: Fix perf regression: remove rx_cqes,
 tx_cqes counters

Hello:

This patch was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@...hat.com>:

On Fri, 26 May 2023 08:38:57 -0700 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [V3,net] net: mana: Fix perf regression: remove rx_cqes, tx_cqes counters
    https://git.kernel.org/netdev/net/c/1919b39fc6ea

You are awesome, thank you!
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