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. -- Florian
