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Date: Sun, 10 Mar 2024 21:19:50 -0700
From: Shradha Gupta <shradhagupta@linux.microsoft.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>,
	Shradha Gupta <shradhagupta@microsoft.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
	"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Eric Dumazet <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>,
	Ajay Sharma <sharmaajay@microsoft.com>,
	Leon Romanovsky <leon@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	KY Srinivasan <kys@microsoft.com>, Wei Liu <wei.liu@kernel.org>,
	Dexuan Cui <decui@microsoft.com>, Long Li <longli@microsoft.com>,
	Michael Kelley <mikelley@microsoft.com>
Subject: Re: [PATCH] net :mana : Add per-cpu stats for MANA device
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On Fri, Mar 08, 2024 at 11:22:44AM -0800, Jakub Kicinski wrote:
> On Fri, 8 Mar 2024 18:51:58 +0000 Haiyang Zhang wrote:
> > > Dynamic is a bit of an exaggeration, right? On a well-configured system
> > > each CPU should use a single queue assigned thru XPS. And for manual
> > > debug bpftrace should serve the purpose quite well.  
> > 
> > Some programs, like irqbalancer can dynamically change the CPU affinity, 
> > so we want to add the per-CPU counters for better understanding of the CPU 
> > usage.
> 
> Do you have experimental data showing this making a difference
> in production?
Sure, will try to get that data for this discussion
> 
> Seems unlikely, but if it does work we should enable it for all
> devices, no driver by driver.
You mean, if the usecase seems valid we should try to extend the framework
mentioned by Rahul (https://lore.kernel.org/lkml/20240307072923.6cc8a2ba@kernel.org/)
to include these stats as well?
Will explore this a bit more and update. Thanks.