| Message ID | 20230728145808.970594909@infradead.org |
|---|---|
| State | New |
| Headers | show |
| Series | cpuidle,teo: Improve TEO tick decisions | expand |
On Fri, Jul 28, 2023 at 07:07:02PM +0200, Rafael J. Wysocki wrote: > On Fri, Jul 28, 2023 at 5:01 PM Peter Zijlstra <peterz@infradead.org> wrote: > > > > When selecting a state, stop when history tells us 66% of recent idles > > were at or below our current state. > > This is not really about "recent idles" AFAICS. It stops the > selection when 66% of the total sum of the "hits" and "intercepts" > signals comes from the current state and the states below it. This > covers the entire history, while the "recent" ones are counted > separately. Ah, bad wording perhaps. I found that 'recent' list teo has very hard to use, also the regular state isn't that long lived as per the reply on the previous patch.
--- a/drivers/cpuidle/governors/teo.c +++ b/drivers/cpuidle/governors/teo.c @@ -363,6 +363,7 @@ static int teo_select(struct cpuidle_dri unsigned int idx_hit_sum = 0; unsigned int hit_sum = 0; unsigned int tick_sum = 0; + unsigned int thresh_sum = 0; int constraint_idx = 0; int idx0 = 0, idx = -1; bool alt_intercepts, alt_recent; @@ -397,6 +398,8 @@ static int teo_select(struct cpuidle_dri duration_ns = tick_nohz_get_sleep_length(&delta_tick); cpu_data->sleep_length_ns = duration_ns; + thresh_sum = 2 * cpu_data->total / 3; /* 66% */ + /* * Find the deepest idle state whose target residency does not exceed * the current sleep length and the deepest idle state not deeper than @@ -427,6 +430,9 @@ static int teo_select(struct cpuidle_dri if (s->target_residency_ns > duration_ns) break; + if (intercept_sum + hit_sum > thresh_sum) + break; + idx = i; if (s->exit_latency_ns <= latency_req)
When selecting a state, stop when history tells us 66% of recent idles were at or below our current state. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- drivers/cpuidle/governors/teo.c | 6 ++++++ 1 file changed, 6 insertions(+)