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| author | Syed Rameez Mustafa <rameezmustafa@codeaurora.org> | 2017-01-03 15:29:14 -0800 |
|---|---|---|
| committer | Syed Rameez Mustafa <rameezmustafa@codeaurora.org> | 2017-01-03 19:22:23 -0800 |
| commit | 3997e768ac8a807af810e038af0ae1f0712a066b (patch) | |
| tree | 2725a24a4b4cc77c1e6b16b0df7b1dee70d78944 /kernel/sched | |
| parent | 2f817b68f06ed866aa2c4cc35b2e4293aeb1ef99 (diff) | |
sched: Fix new task accounting bug in transfer_busy_time()
In transfer_busy_time(), the new_task flag is set based on the active
window count prior to the call to update_task_ravg(). update_task_ravg()
however, can then increment the active window count and consequently
the new_task flag above becomes stale. This is turn leads to inaccurate
accounting whereby update_task_ravg() does accounting based on the fact
that the task is not new whereas transfer_busy_time() then continues to
do further accounting assuming that the task is new. The accounting
discrepancies are sometimes caught by some of the scheduler BUGs.
Fix the described problem by moving the check is_new_task() after the
call to update_task_ravg(). Also add two missing BUGs that would catch
the problem sooner rather than later.
Change-Id: I8dc4822e97cc03ebf2ca1ee2de95eb4e5851f459
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/hmp.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/sched/hmp.c b/kernel/sched/hmp.c index a8bf39c6d7d7..0c3ab3d45a2f 100644 --- a/kernel/sched/hmp.c +++ b/kernel/sched/hmp.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved. +/* Copyright (c) 2012-2017, The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and @@ -3897,7 +3897,7 @@ static void transfer_busy_time(struct rq *rq, struct related_thread_group *grp, struct migration_sum_data d; int migrate_type; int cpu = cpu_of(rq); - bool new_task = is_new_task(p); + bool new_task; int i; if (!sched_freq_aggregate) @@ -3907,6 +3907,7 @@ static void transfer_busy_time(struct rq *rq, struct related_thread_group *grp, update_task_ravg(rq->curr, rq, TASK_UPDATE, wallclock, 0); update_task_ravg(p, rq, TASK_UPDATE, wallclock, 0); + new_task = is_new_task(p); /* cpu_time protected by related_thread_group_lock, grp->lock rq_lock */ cpu_time = _group_cpu_time(grp, cpu); @@ -4001,6 +4002,8 @@ static void transfer_busy_time(struct rq *rq, struct related_thread_group *grp, BUG_ON((s64)*src_curr_runnable_sum < 0); BUG_ON((s64)*src_prev_runnable_sum < 0); + BUG_ON((s64)*src_nt_curr_runnable_sum < 0); + BUG_ON((s64)*src_nt_prev_runnable_sum < 0); } static inline struct group_cpu_time * |