On 03/09/2019 09:28, Ming Lei wrote: > On Tue, Sep 03, 2019 at 08:40:35AM +0200, Daniel Lezcano wrote: >> On 03/09/2019 08:31, Ming Lei wrote: >>> Hi Daniel, >>> >>> On Tue, Sep 03, 2019 at 07:59:39AM +0200, Daniel Lezcano wrote: >>>> >>>> Hi Ming Lei, >>>> >>>> On 03/09/2019 05:30, Ming Lei wrote: >>>> >>>> [ ... ] >>>> >>>> >>>>>>> 2) irq/timing doesn't cover softirq >>>>>> >>>>>> That's solvable, right? >>>>> >>>>> Yeah, we can extend irq/timing, but ugly for irq/timing, since irq/timing >>>>> focuses on hardirq predication, and softirq isn't involved in that >>>>> purpose. >>>>> >>>>>> >>>>>>> Daniel, could you take a look and see if irq flood detection can be >>>>>>> implemented easily by irq/timing.c? >>>>>> >>>>>> I assume you can take a look as well, right? >>>>> >>>>> Yeah, I have looked at the code for a while, but I think that irq/timing >>>>> could become complicated unnecessarily for covering irq flood detection, >>>>> meantime it is much less efficient for detecting IRQ flood. >>>> >>>> In the series, there is nothing describing rigorously the problem (I can >>>> only guess) and why the proposed solution solves it. >>>> >>>> What is your definition of an 'irq flood'? A high irq load? An irq >>>> arriving while we are processing the previous one in the bottom halves? >>> >>> So far, it means that handling interrupt & softirq takes all utilization >>> of one CPU, then processes can't be run on this CPU basically, usually >>> sort of CPU lockup warning will be triggered. >> >> It is a scheduler problem then ? > > Scheduler can do nothing if the CPU is taken completely by handling > interrupt & softirq, so seems not a scheduler problem, IMO. Why? If there is a irq pressure on one CPU reducing its capacity, the scheduler will balance the tasks on another CPU, no? -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
