[PATCH v4 0/5] Make find_later_rq() choose a closer cpu in topology
Change from v3 -. rename closest_cpu to best_cpu so that it align with rt -. protect referring cpudl.elements with cpudl.lock -. change return value of cpudl_find() to bool Change from v2 -. add support for SD_PREFER_SIBLING Change from v1 -. clean up the patch When cpudl_find() returns any among free_cpus, the cpu might not be closer than others, considering sched domain. For example: this_cpu: 15 free_cpus: 0, 1,..., 14 (== later_mask) best_cpu: 0 topology: 0 --+ +--+ 1 --+ | +-- ... --+ 2 --+ | | +--+ | 3 --+| ... ... 12 --+ | +--+| 13 --+ || +-- ... -+ 14 --+ | +--+ 15 --+ In this case, it would be best to select 14 since it's a free cpu and closest to 15(this_cpu). However, currently the code select 0(best_cpu) even though that's just any among free_cpus. Fix it. Byungchul Park (5): sched/deadline: Refer to cpudl.elements atomically sched/deadline: Make find_later_rq() choose a closer cpu in topology sched/deadline: Change return value of cpudl_find() sched/deadline: Add support for SD_PREFER_SIBLING on find_later_rq() sched/rt: Add support for SD_PREFER_SIBLING on find_lowest_rq() kernel/sched/cpudeadline.c | 46 +++- kernel/sched/deadline.c| 48 +++--- kernel/sched/rt.c | 17 3 files changed, 83 insertions(+), 28 deletions(-) -- 1.9.1
[PATCH v4 0/5] Make find_later_rq() choose a closer cpu in topology
Change from v3 -. rename closest_cpu to best_cpu so that it align with rt -. protect referring cpudl.elements with cpudl.lock -. change return value of cpudl_find() to bool Change from v2 -. add support for SD_PREFER_SIBLING Change from v1 -. clean up the patch When cpudl_find() returns any among free_cpus, the cpu might not be closer than others, considering sched domain. For example: this_cpu: 15 free_cpus: 0, 1,..., 14 (== later_mask) best_cpu: 0 topology: 0 --+ +--+ 1 --+ | +-- ... --+ 2 --+ | | +--+ | 3 --+| ... ... 12 --+ | +--+| 13 --+ || +-- ... -+ 14 --+ | +--+ 15 --+ In this case, it would be best to select 14 since it's a free cpu and closest to 15(this_cpu). However, currently the code select 0(best_cpu) even though that's just any among free_cpus. Fix it. Byungchul Park (5): sched/deadline: Refer to cpudl.elements atomically sched/deadline: Make find_later_rq() choose a closer cpu in topology sched/deadline: Change return value of cpudl_find() sched/deadline: Add support for SD_PREFER_SIBLING on find_later_rq() sched/rt: Add support for SD_PREFER_SIBLING on find_lowest_rq() kernel/sched/cpudeadline.c | 46 +++- kernel/sched/deadline.c| 48 +++--- kernel/sched/rt.c | 17 3 files changed, 83 insertions(+), 28 deletions(-) -- 1.9.1
