Messages in this thread | | | From | Chengming Zhou <> | Subject | [PATCH v3 00/10] sched/fair: task load tracking optimization and cleanup | Date | Mon, 1 Aug 2022 12:27:35 +0800 |
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Hi all,
This patch series is optimization and cleanup for task load tracking when task migrate CPU/cgroup or switched_from/to_fair().
There are three types of detach/attach_entity_load_avg (except fork and exit case) for a fair task: 1. task migrate CPU (on_rq migrate or wake_up migrate) 2. task migrate cgroup (detach and attach) 3. task switched_from/to_fair (detach later attach)
patch 01-03 cleanup the task change cgroup case by remove cpu_cgrp_subsys->fork(), since we already do the same thing in sched_cgroup_fork().
patch 05 optimize the task migrate CPU case by combine detach into dequeue.
patch 06 fix another detach on unattached task case which has been woken up by try_to_wake_up() but is waiting for actually being woken up by sched_ttwu_pending().
patch 07 remove unnecessary limitation that we would fail when change cgroup of forked task which hasn't been woken up by wake_up_new_task().
patch 08 refactor detach/attach_entity_cfs_rq by using update_load_avg() DO_DETACH and DO_ATTACH flags.
patch 09-10 optimize post_init_entity_util_avg() for fair task and skip setting util_avg and runnable_avg for !fair task.
Thanks!
Changes in v3: - One big change is this series don't freeze PELT sum/avg values to be used as initial values when re-entering fair any more, since these PELT values become much less relevant. - Reorder patches and collect tags from Vincent and Dietmar. Thanks! - Fix detach on unattached task which has been woken up by try_to_wake_up() but is waiting for actually being woken up by sched_ttwu_pending(). - Delete TASK_NEW which limit forked task from changing cgroup. - Don't init util_avg and runnable_avg for !fair taks at fork time.
Changes in v2: - split task se depth maintenance into a separate patch3, suggested by Peter. - reorder patch6-7 before patch8-9, since we need update_load_avg() to do conditional attach/detach to avoid corner cases like twice attach problem.
Chengming Zhou (10): sched/fair: maintain task se depth in set_task_rq() sched/fair: remove redundant cpu_cgrp_subsys->fork() sched/fair: reset sched_avg last_update_time before set_task_rq() sched/fair: update comments in enqueue/dequeue_entity() sched/fair: combine detach into dequeue when migrating task sched/fair: fix another detach on unattached task corner case sched/fair: allow changing cgroup of new forked task sched/fair: refactor detach/attach_entity_cfs_rq using update_load_avg() sched/fair: defer task sched_avg attach to enqueue_entity() sched/fair: don't init util/runnable_avg for !fair task
include/linux/sched.h | 5 +- kernel/sched/core.c | 57 ++-------- kernel/sched/fair.c | 242 ++++++++++++++++++------------------------ kernel/sched/sched.h | 6 +- 4 files changed, 119 insertions(+), 191 deletions(-)
-- 2.36.1
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