diff options
| author | Pavankumar Kondeti <pkondeti@codeaurora.org> | 2017-06-08 15:19:48 +0530 |
|---|---|---|
| committer | Pavankumar Kondeti <pkondeti@codeaurora.org> | 2017-06-09 06:40:02 +0530 |
| commit | a761ae85013944d6e007a343c7f24c342ae4dc18 (patch) | |
| tree | 301f4502e3335f97e2cc86f96cb2ab6ac2b6ad56 | |
| parent | 9725c4d90bee3b0be78bb1fdc084df1ec08d7d24 (diff) | |
sched: Fix the bug in select_best_cpu() that returns -1 as target_cpu
select_best_cpu() has previous CPU's cluster bias which overrides
the best_cpu with best_sibling_cpu when the power cost is same.
When the power table is configured incorrectly or static_cpu_pwr_cost/
static_cluster_pwr_cost tunables are set to a large value, the
power_cost() for all candidate CPUs can return INT_MAX. So the
stats.min_cost is never changed from it's initial value i.e INT_MAX.
In the above scenario, we find stats.best_cpu >= 0 && stats.min_cost =
stats.best_sibling_cpu_cost = INT_MAX && stats.best_sibling_cpu_cost = -1
and replace best_cpu with best_sibling_cpu i.e -1.
Change-Id: I09829e278e41daaaff959428ff50927aba29104c
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
| -rw-r--r-- | kernel/sched/fair.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9abc3e65dbd9..ef00eaf41317 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3240,7 +3240,8 @@ retry: sbc_flag |= SBC_FLAG_IDLE_LEAST_LOADED; } } else if (stats.best_cpu >= 0) { - if (stats.best_cpu != task_cpu(p) && + if (stats.best_sibling_cpu >= 0 && + stats.best_cpu != task_cpu(p) && stats.min_cost == stats.best_sibling_cpu_cost) { stats.best_cpu = stats.best_sibling_cpu; sbc_flag |= SBC_FLAG_BEST_SIBLING; |