On Mon, Feb 06, 2023 at 04:51:09PM +0100, Michal Koutný wrote: > Hello Frederic. > > On Sat, Feb 04, 2023 at 12:24:08AM +0100, Frederic Weisbecker <frederic@xxxxxxxxxx> wrote: > > The individual isolation features turned on by nohz_full were initially > > split in order for each of them to be tunable through cpusets. However > > plans have changed in favour of an interface (be it cpusets or sysctl) > > grouping all these features to be turned on/off altogether. > > Then should the need ever arise, the interface can still be expanded > > to handle the individual isolation features. > > > > Therefore the current isolation split between tick/timer/workqueue/rcu/ > > kthreads/misc doesn't make sense anymore. > > Why it doesn't make sense? I think it's a useful annotation of > respective operations wrt CPU isolation. But what do we need these annotations for? The only outcome I've ever seen with these is that it confuses everyone. > > The grouping you did into HK_TYPE_KERNEL_NOISE (or even coarser) should > IMO be done at the place where it'll be exposed into the favored > interface (like it's with nohz_full=). That being said I should reserve the grouping to HK_TYPE_KERNEL_NOISE when I'll introduce the cpuset interface. This way I can add the support for each part smoothly. For example first patch moves HK_TYPE_TIMER to HK_TYPE_KERNEL_NOISE and unbound timers are supported by cpuset.kernel_noise, second patch moves HK_TYPE_WQ to HK_TYPE_KERNEL_NOISE and unbound workqueues are supported by cpuset.kernel_noise, etc until all of them turned by nohz_full= are supported... This is what I'm doing in fact but I'm so slow to write this patchset... Thanks.
