> -----Original Message----- > From: Jakub Kicinski <kuba@xxxxxxxxxx> > Sent: Friday, March 8, 2024 2:23 PM > To: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> > Cc: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>; Shradha Gupta > <shradhagupta@xxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; linux- > hyperv@xxxxxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx; > netdev@xxxxxxxxxxxxxxx; Eric Dumazet <edumazet@xxxxxxxxxx>; Paolo Abeni > <pabeni@xxxxxxxxxx>; Ajay Sharma <sharmaajay@xxxxxxxxxxxxx>; Leon > Romanovsky <leon@xxxxxxxxxx>; Thomas Gleixner <tglx@xxxxxxxxxxxxx>; > Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>; KY Srinivasan > <kys@xxxxxxxxxxxxx>; Wei Liu <wei.liu@xxxxxxxxxx>; Dexuan Cui > <decui@xxxxxxxxxxxxx>; Long Li <longli@xxxxxxxxxxxxx>; Michael Kelley > <mikelley@xxxxxxxxxxxxx> > Subject: Re: [PATCH] net :mana : Add per-cpu stats for MANA device > > 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? Shradha, could you please add some data before / after enabling irqbalancer which changes cpu affinity? > > Seems unlikely, but if it does work we should enable it for all > devices, no driver by driver. There are some existing drivers, like mlx, rmnet, netvsc, etc. using percpu counters. Are you suggesting we add a common API for all drivers? Thanks, - Haiyang
