-----Original Message----- From: Jakub Kicinski kuba@kernel.org Sent: Thursday, May 25, 2023 11:26 PM To: Haiyang Zhang haiyangz@microsoft.com Cc: linux-hyperv@vger.kernel.org; netdev@vger.kernel.org; Dexuan Cui decui@microsoft.com; KY Srinivasan kys@microsoft.com; Paul Rosswurm paulros@microsoft.com; olaf@aepfle.de; vkuznets@redhat.com; davem@davemloft.net; wei.liu@kernel.org; edumazet@google.com; pabeni@redhat.com; leon@kernel.org; Long Li longli@microsoft.com; ssengar@linux.microsoft.com; linux-rdma@vger.kernel.org; daniel@iogearbox.net; john.fastabend@gmail.com; bpf@vger.kernel.org; ast@kernel.org; Ajay Sharma sharmaajay@microsoft.com; hawk@kernel.org; tglx@linutronix.de; shradhagupta@linux.microsoft.com; linux-kernel@vger.kernel.org; stable@vger.kernel.org Subject: Re: [PATCH V2,net] net: mana: Fix perf regression: remove rx_cqes, tx_cqes counters
On Thu, 25 May 2023 07:46:30 -0700 Haiyang Zhang wrote:
lot caching and memory overhead, hence perf regression.
Horatiu's ask for more details was perfectly reasonable. Provide more details to give the distros and users an idea of the order of magnitude of the problem. Example workload and relative perf hit, anything.
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.
Thanks, - Haiyang