On Thu, 2018-01-11 at 12:40 -0800, Linus Torvalds wrote: > On Thu, Jan 11, 2018 at 12:34 PM, Dmitry Safonov <d...@arista.com> > wrote: > > > > I could try to write a PoC for that.. > > What should be the trigger to fall into workqueue? > > How to tell if there're too many softirqs of the kind? > > I suspect it would have to be time-based, probably using the > scheduler clock.
I thought about this, but I was a bit afraid of how much pricey it would be recalculate it each clock. Well, might just try to write that and measure the impact. > Most softirqs are really really small. So just counting them probably > isn't all that meaningful, although the count is good as a fallback > (as shown by the jiffy issues). > > The good news is that we only have a fairly small handful of > softirqs, > so counting/timing them separately is still mainly a pretty small > array (which needs to be percpu, of course).