Messages in this thread | | | From | byungchul.park@lge ... | Subject | [PATCH v4 0/5] sync a se with its cfs_rq when att(det)aching it | Date | Thu, 20 Aug 2015 20:21:55 +0900 |
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From: Byungchul Park <byungchul.park@lge.com>
there are 3 problems when att(det)aching a se to(from) its cfs_rq.
problem 1. se's average load is not accounted with new cfs_rq in queued case, when a task changes its cgroup.
problem 2. cfs_rq->avg.load_avg becomes larger and larger whenever changing cgroup to another. we have to sync se's average load with prev cfs_rq.
problem 3. current code does not sync it with its cfs_rq when switching sched class to fair class. if we can always assume that a se has been detached from fair class for a long time enough for its average load to become useless, at the time attaching it to its fair class cfs_rq, then current code is acceptable. but the assumption is not always true.
patch 1/5, does code refactoring for further patches. patch 2/5, solves the problem 1. patch 3/5, solves the problem 2. patch 4/5, solves the problem 3. patch 5/5, does code refactoring for better readability.
change from v3 to v4 * clean up code as Peter suggests * use upper case letter in comment properly
change from v2 to v3 (logic is same as v2) * fix up my poor english in commit message and comment * break down big patches into more patches for being reviewed easily * supplement cover letter messages
change from v1 to v2 * introduce two functions for adjusting vruntime and load when attaching and detaching. * call the introduced functions instead of switched_from(to)_fair() directly in task_move_group_fair(). * add decaying logic for a se which has detached from a cfs_rq.
thanks, byungchul
Byungchul Park (5): sched: add two functions adjusting cfs_rq's load when att(det)aching a se sched: make task_move_group_fair adjust cfs_rq's load in case of queued sched: sync a se with prev cfs_rq when changing cgroup sched: sync a se with its cfs_rq when switching sched class to fair class sched: add two functions for att(det)aching a task to(from) a cfs_rq
kernel/sched/fair.c | 222 ++++++++++++++++++++++++++------------------------- 1 file changed, 113 insertions(+), 109 deletions(-)
-- 1.7.9.5
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