> -----Original Message----- > From: Florian Fainelli <f.fainelli@xxxxxxxxx> > Sent: Friday, July 24, 2020 12:33 AM > To: Rakesh Pillai <pillair@xxxxxxxxxxxxxx>; 'Andrew Lunn' > <andrew@xxxxxxx> > Cc: ath10k@xxxxxxxxxxxxxxxxxxx; linux-wireless@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; kvalo@xxxxxxxxxxxxxx; johannes@xxxxxxxxxxxxxxxx; > davem@xxxxxxxxxxxxx; kuba@xxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; > dianders@xxxxxxxxxxxx; evgreen@xxxxxxxxxxxx > Subject: Re: [RFC 0/7] Add support to process rx packets in thread > > On 7/23/20 11:21 AM, Rakesh Pillai wrote: > > > > > >> -----Original Message----- > >> From: Florian Fainelli <f.fainelli@xxxxxxxxx> > >> Sent: Tuesday, July 21, 2020 11:35 PM > >> To: Andrew Lunn <andrew@xxxxxxx>; Rakesh Pillai > <pillair@xxxxxxxxxxxxxx> > >> Cc: ath10k@xxxxxxxxxxxxxxxxxxx; linux-wireless@xxxxxxxxxxxxxxx; linux- > >> kernel@xxxxxxxxxxxxxxx; kvalo@xxxxxxxxxxxxxx; > johannes@xxxxxxxxxxxxxxxx; > >> davem@xxxxxxxxxxxxx; kuba@xxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; > >> dianders@xxxxxxxxxxxx; evgreen@xxxxxxxxxxxx > >> Subject: Re: [RFC 0/7] Add support to process rx packets in thread > >> > >> On 7/21/20 10:25 AM, Andrew Lunn wrote: > >>> On Tue, Jul 21, 2020 at 10:44:19PM +0530, Rakesh Pillai wrote: > >>>> NAPI gets scheduled on the CPU core which got the > >>>> interrupt. The linux scheduler cannot move it to a > >>>> different core, even if the CPU on which NAPI is running > >>>> is heavily loaded. This can lead to degraded wifi > >>>> performance when running traffic at peak data rates. > >>>> > >>>> A thread on the other hand can be moved to different > >>>> CPU cores, if the one on which its running is heavily > >>>> loaded. During high incoming data traffic, this gives > >>>> better performance, since the thread can be moved to a > >>>> less loaded or sometimes even a more powerful CPU core > >>>> to account for the required CPU performance in order > >>>> to process the incoming packets. > >>>> > >>>> This patch series adds the support to use a high priority > >>>> thread to process the incoming packets, as opposed to > >>>> everything being done in NAPI context. > >>> > >>> I don't see why this problem is limited to the ath10k driver. I expect > >>> it applies to all drivers using NAPI. So shouldn't you be solving this > >>> in the NAPI core? Allow a driver to request the NAPI core uses a > >>> thread? > >> > >> What's more, you should be able to configure interrupt affinity to steer > >> RX processing onto a desired CPU core, is not that working for you > >> somehow? > > > > Hi Florian, > > Yes, the affinity of IRQ does work for me. > > But the affinity of IRQ does not happen runtime based on load. > > It can if you also run irqbalance. Hi Florian, Is it some kernel feature ? Sorry I am not aware of this ? I know it can be done in userspace. > -- > Florian
