On 23-Jan 10:22, Peter Zijlstra wrote: > On Tue, Jan 22, 2019 at 03:41:29PM +0000, Patrick Bellasi wrote: > > On 22-Jan 16:13, Peter Zijlstra wrote: > > > On Tue, Jan 22, 2019 at 02:43:29PM +0000, Patrick Bellasi wrote: > > > > > Do you think that could be acceptable? > > > > > > Think so, it's a sysctl poke, 'nobody' ever does that. > > > > Cool, so... I'll keep lazy update for system default. > > Ah, I think I misunderstood. I meant to say that since nobody ever pokes > at sysctl's it doesn't matter if its a little more expensive and iterate > everything. Here I was more worried about the code complexity/overhead... for something actually not very used/useful. > Also; if you always keep everything up-to-date, you can avoid doing that > duplicate accounting. To update everything we will have to walk all the CPUs and update all the RUNNABLE tasks currently enqueued, which are either RT or CFS. That's way more expensive both in code and time then what we do for cgroups, where at least we have a limited scope since the cgroup already provides a (usually limited) list of tasks to consider. Do you think it's really worth to have ? Perhaps we can add it in a second step, once we have the core bits in and we really see a need for a specific use-case. -- #include <best/regards.h> Patrick Bellasi
