On Mon 27-03-23 07:24:54, Marcelo Tosatti wrote: > On Fri, Mar 24, 2023 at 11:35:35PM +0100, Frederic Weisbecker wrote: > > Le Sat, Mar 18, 2023 at 09:04:38AM +0100, Michal Hocko a écrit : > > > On Fri 17-03-23 15:35:05, Marcelo Tosatti wrote: [...] > > > > Actually introducing cpu_is_isolated() seems fine, but it can call > > > > housekeeping_test_cpu(cpu, HK_TYPE_TICK) AFAICS. > > > > > > This is not really my area. Frederic, could you have a look please? > > > > The point is to have a function that tells if either nohz_full= or > > isolcpus=[domain] has been passed for the given CPU. > > > > Because I assumed that both would be interested in avoiding that flush > > noise, wouldn't it be the case? > > Yes, that is the case. But as a note: for the two main types of > configuration performed (one uses isolcpus=[domain] and the other > cgroups, for isolating processes) nohz_full= is always set. > > So just testing for nohz_full= would be sufficient (which perhaps would > make the code simpler). I do not see any mention about that assumption under Documentation/. Is this a best practice documented anywhere or it just happens to be the case with workloads you deal with? -- Michal Hocko SUSE Labs
