On 27/10/2020 04:32, Xuewen Yan wrote: > the highest_flag_domain is to search the highest sched_domain > containing flag, but if the lower sched_domain didn't contain > the flag, but the higher sched_domain contains the flag, the > function will return NULL instead of the higher sched_domain. > > For example: > In MC domain : no SD_ASYM_CPUCAPACITY flag; > In DIE domain : containing SD_ASYM_CPUCAPACITY flag; > the "highest_flag_domain(cpu, SD_ASYM_CPUCAPACITY)" will return NULL. > > Signed-off-by: Xuewen Yan <xuewen.ya...@gmail.com> > --- > kernel/sched/sched.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h > index 28709f6..2c7c566 100644 > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -1427,7 +1427,7 @@ static inline struct sched_domain > *highest_flag_domain(int cpu, int flag) > > for_each_domain(cpu, sd) { > if (!(sd->flags & flag)) > - break; > + continue; > hsd = sd; > }
We distinguish between SDF_SHARED_PARENT and SDF_SHARED_CHILD SD flags. 1 SD_FLAG(*SD_ASYM_CPUCAPACITY*, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) 2 SD_FLAG(SD_SERIALIZE, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) 3 SD_FLAG(SD_OVERLAP, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) 4 SD_FLAG(SD_NUMA, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) 1 SD_FLAG(SD_BALANCE_NEWIDLE, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) 2 SD_FLAG(SD_BALANCE_EXEC, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) 3 SD_FLAG(SD_BALANCE_FORK, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) 4 SD_FLAG(SD_BALANCE_WAKE, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) 5 82 SD_FLAG(SD_WAKE_AFFINE, SDF_SHARED_CHILD) 6 SD_FLAG(SD_SHARE_CPUCAPACITY, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) 7 SD_FLAG(SD_SHARE_PKG_RESOURCES, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) 8 SD_FLAG(SD_ASYM_PACKING, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) We call lowest_flag_domain() on SDF_SHARED_PARENT and highest_flag_domain() on SDF_SHARED_CHILD SD flags. 1 sd = lowest_flag_domain(cpu, SD_NUMA); 2 sd = lowest_flag_domain(cpu, *SD_ASYM_CPUCAPACITY*); 1 sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES); 2 sd = highest_flag_domain(cpu, SD_ASYM_PACKING);