From: Peter Zijlstra <peterz@infradead.org>
To: anna-maria@linutronix.de, rafael@kernel.org, tglx@linutronix.de,
frederic@kernel.org, gautham.shenoy@amd.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
daniel.lezcano@linaro.org, linux-pm@vger.kernel.org,
mingo@redhat.com, juri.lelli@redhat.com,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
bristot@redhat.com, vschneid@redhat.com,
kajetan.puchalski@arm.com
Subject: [RFC][PATCH v2 3/5] cpuidle/teo: Simplify a little
Date: Wed, 02 Aug 2023 15:24:34 +0200 [thread overview]
Message-ID: <20230802132925.686745535@infradead.org> (raw)
In-Reply-To: 20230802132431.254614419@infradead.org
Remove some of the early exit cases that rely on state_count, since we
have the additional tick state. Declutters some of the next patches, can
possibly be re-instated later if desired.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
drivers/cpuidle/governors/teo.c | 31 +------------------------------
1 file changed, 1 insertion(+), 30 deletions(-)
--- a/drivers/cpuidle/governors/teo.c
+++ b/drivers/cpuidle/governors/teo.c
@@ -187,7 +187,6 @@ struct teo_bin {
* @next_recent_idx: Index of the next @recent_idx entry to update.
* @recent_idx: Indices of bins corresponding to recent "intercepts".
* @util_threshold: Threshold above which the CPU is considered utilized
- * @utilized: Whether the last sleep on the CPU happened while utilized
*/
struct teo_cpu {
s64 time_span_ns;
@@ -197,7 +196,6 @@ struct teo_cpu {
int next_recent_idx;
int recent_idx[NR_RECENT];
unsigned long util_threshold;
- bool utilized;
};
static DEFINE_PER_CPU(struct teo_cpu, teo_cpus);
@@ -379,33 +377,6 @@ static int teo_select(struct cpuidle_dri
duration_ns = tick_nohz_get_sleep_length(&delta_tick);
cpu_data->sleep_length_ns = duration_ns;
- /* Check if there is any choice in the first place. */
- if (drv->state_count < 2) {
- idx = 0;
- goto end;
- }
- if (!dev->states_usage[0].disable) {
- idx = 0;
- if (drv->states[1].target_residency_ns > duration_ns)
- goto end;
- }
-
- cpu_data->utilized = teo_cpu_is_utilized(dev->cpu, cpu_data);
- /*
- * If the CPU is being utilized over the threshold and there are only 2
- * states to choose from, the metrics need not be considered, so choose
- * the shallowest non-polling state and exit.
- */
- if (drv->state_count < 3 && cpu_data->utilized) {
- for (i = 0; i < drv->state_count; ++i) {
- if (!dev->states_usage[i].disable &&
- !(drv->states[i].flags & CPUIDLE_FLAG_POLLING)) {
- idx = i;
- goto end;
- }
- }
- }
-
/*
* Find the deepest idle state whose target residency does not exceed
* the current sleep length and the deepest idle state not deeper than
@@ -541,7 +512,7 @@ static int teo_select(struct cpuidle_dri
* If the CPU is being utilized over the threshold, choose a shallower
* non-polling state to improve latency
*/
- if (cpu_data->utilized)
+ if (teo_cpu_is_utilized(dev->cpu, cpu_data))
idx = teo_find_shallower_state(drv, dev, idx, duration_ns, true);
end:
next prev parent reply other threads:[~2023-08-02 13:31 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-02 13:24 [RFC][PATCH v2 0/5] cpuidle,teo: Improve TEO vs NOHZ Peter Zijlstra
2023-08-02 13:24 ` [RFC][PATCH v2 1/5] tick/nohz: Introduce tick_get_sleep_length() Peter Zijlstra
2023-08-02 13:24 ` [RFC][PATCH v2 2/5] cpuidle: Inject tick boundary state Peter Zijlstra
2023-08-02 13:24 ` Peter Zijlstra [this message]
2023-08-03 10:12 ` [RFC][PATCH v2 3/5] cpuidle/teo: Simplify a little Kajetan Puchalski
2023-08-02 13:24 ` [RFC][PATCH v2 4/5] cpuidle/teo: Avoid tick_nohz_next_event() Peter Zijlstra
2023-08-02 13:24 ` [RFC][PATCH v2 5/5] cpuidle,teo: Improve state selection Peter Zijlstra
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