On Thu, 2018-01-18 at 05:09 +0100, Frederic Weisbecker wrote: > On Wed, Jan 17, 2018 at 07:09:39PM -0800, Linus Torvalds wrote: > > It should never trigger under any normal load, but I think it > > *should* > > trigger under the load that the networking people worry about. If > > you > > get a flood of UDP packets, and spend a lot of time in softirqs, > > I'm > > pretty sure you'd hit that case of seeing the same softirq re- > > raised > > fairly naturally and quickly. > > Ok after a quick tracing check, it seems that executing the same > softirq > vector twice in the same interrupt does not happen without much > stress.
Uhm, yes it should.. but that was what I originally saw on hw - that raising a new softirq under UDP packet storm might happen slower than expected. And a new softirq is raised only after the first one was processed. Which results in rare deferring. -- Dima