Messages in this thread | | | Subject | Re: [PATCH 1/4] softirq: implement IRQ flood detection mechanism | From | Bart Van Assche <> | Date | Wed, 4 Sep 2019 10:07:48 -0700 |
| |
On 9/3/19 12:50 AM, Daniel Lezcano wrote: > On 03/09/2019 09:28, Ming Lei wrote: >> On Tue, Sep 03, 2019 at 08:40:35AM +0200, Daniel Lezcano wrote: >>> 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?
Only if CONFIG_IRQ_TIME_ACCOUNTING has been enabled. However, I don't know any Linux distro that enables that option. That's probably because that option introduces two rdtsc() calls in each interrupt. Given the overhead introduced by this option, I don't think this is the solution Ming is looking for.
See also irqtime_account_irq() in kernel/sched/cputime.c.
Bart.
| |