On Mon, 17 May 2021 at 10:24, Beata Michalska <beata.michalska@xxxxxxx> wrote: > > Introducing new, complementary to SD_ASYM_CPUCAPACITY, sched_domain > topology flag, to distinguish between shed_domains where any CPU > capacity asymmetry is detected (SD_ASYM_CPUCAPACITY) and ones where > a full range of CPU capacities is visible to all domain members > (SD_ASYM_CPUCAPACITY_FULL). I'm not sure about what you want to detect: Is it a sched_domain level with a full range of cpu capacity, i.e. with at least 1 min capacity and 1 max capacity ? or do you want to get at least 1 cpu of each capacity ? > > With the distinction between full and partial CPU capacity asymmetry, > brought in by the newly introduced flag, the scope of the original > SD_ASYM_CPUCAPACITY flag gets shifted, still maintaining the existing > behaviour when one is detected on a given sched domain, allowing > misfit migrations within sched domains that do not observe full range > of CPU capacities but still do have members with different capacity > values. It loses though it's meaning when it comes to the lowest CPU > asymmetry sched_domain level per-cpu pointer, which is to be now > denoted by SD_ASYM_CPUCAPACITY_FULL flag. > > Signed-off-by: Beata Michalska <beata.michalska@xxxxxxx> > Reviewed-by: Valentin Schneider <valentin.schneider@xxxxxxx> > --- > include/linux/sched/sd_flags.h | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/include/linux/sched/sd_flags.h b/include/linux/sched/sd_flags.h > index 34b21e9..57bde66 100644 > --- a/include/linux/sched/sd_flags.h > +++ b/include/linux/sched/sd_flags.h > @@ -91,6 +91,16 @@ SD_FLAG(SD_WAKE_AFFINE, SDF_SHARED_CHILD) > SD_FLAG(SD_ASYM_CPUCAPACITY, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) > > /* > + * Domain members have different CPU capacities spanning all unique CPU > + * capacity values. > + * > + * SHARED_PARENT: Set from the topmost domain down to the first domain where > + * all available CPU capacities are visible > + * NEEDS_GROUPS: Per-CPU capacity is asymmetric between groups. > + */ > +SD_FLAG(SD_ASYM_CPUCAPACITY_FULL, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) > + > +/* > * Domain members share CPU capacity (i.e. SMT) > * > * SHARED_CHILD: Set from the base domain up until spanned CPUs no longer share > -- > 2.7.4 >
