diff options
| author | Vikram Mulukutla <markivx@codeaurora.org> | 2017-08-10 17:26:20 -0700 |
|---|---|---|
| committer | Georg Veichtlbauer <georg@vware.at> | 2023-07-16 12:47:43 +0200 |
| commit | 0fa652ee00f5aaf9fdebea0e0f840e59bdb6795b (patch) | |
| tree | ade760132a61de5196e957779596642ee73ac4e5 | |
| parent | 41cbb7bc59fb94f020839f20b890033e2f407ca3 (diff) | |
sched: walt: Correct WALT window size initialization
It is preferable that WALT window rollover occurs just
before a tick, since the tick is an opportune moment
to record a complete window's statistics, as well as report
those stats to the cpu frequency governor. When CONFIG_HZ
results in a TICK_NSEC that isn't a integral number, this
requirement may be violated. Account for this by reducing
the WALT window size to the nearest multiple of TICK_NSEC.
Commit d368c6faa19b ("sched: walt: fix window misalignment
when HZ=300") attempted to do this but WALT isn't using
MIN_SCHED_RAVG_WINDOW as the window size and the patch was
doing nothing.
Also, change the type of 'walt_disabled' to bool and warn
if an invalid window size causes WALT to be disabled.
[beykerykt]: Adapt for HMP
Change-Id: Ie3dcfc21a3df4408254ca1165a355bbe391ed5c7
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
| -rw-r--r-- | kernel/sched/hmp.c | 32 |
1 files changed, 15 insertions, 17 deletions
diff --git a/kernel/sched/hmp.c b/kernel/sched/hmp.c index f9fff7217eaa..1755e919f8f4 100644 --- a/kernel/sched/hmp.c +++ b/kernel/sched/hmp.c @@ -765,20 +765,15 @@ unsigned int min_max_possible_capacity = 1024; /* min(rq->max_possible_capacity) */ /* Min window size (in ns) = 10ms */ -#ifdef CONFIG_HZ_300 -/* - * Tick interval becomes to 3333333 due to - * rounding error when HZ=300. - */ -#define MIN_SCHED_RAVG_WINDOW (3333333 * 6) -#else -#define MIN_SCHED_RAVG_WINDOW 10000000 -#endif +#define MIN_SCHED_RAVG_WINDOW ((10000000 / TICK_NSEC) * TICK_NSEC) /* Max window size (in ns) = 1s */ -#define MAX_SCHED_RAVG_WINDOW 1000000000 +#define MAX_SCHED_RAVG_WINDOW ((1000000000 / TICK_NSEC) * TICK_NSEC) -/* Window size (in ns) */ +/* + * Window size (in ns). Adjust for the tick size so that the window + * rollover occurs just before the tick boundary. + */ __read_mostly unsigned int sched_ravg_window = MIN_SCHED_RAVG_WINDOW; /* Maximum allowed threshold before freq aggregation must be enabled */ @@ -1624,17 +1619,20 @@ static inline int exiting_task(struct task_struct *p) static int __init set_sched_ravg_window(char *str) { + unsigned int adj_window; unsigned int window_size; get_option(&str, &window_size); - if (window_size < MIN_SCHED_RAVG_WINDOW || - window_size > MAX_SCHED_RAVG_WINDOW) { - WARN_ON(1); - return -EINVAL; - } + /* Adjust for CONFIG_HZ */ + adj_window = (window_size / TICK_NSEC) * TICK_NSEC; + + /* Warn if we're a bit too far away from the expected window size */ + WARN(adj_window < window_size - NSEC_PER_MSEC, + "tick-adjusted window size %u, original was %u\n", adj_window, + window_size); - sched_ravg_window = window_size; + sched_ravg_window = adj_window; return 0; } |