From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Christian Loehle <christian.loehle@arm.com>,
Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Subject: [PATCH v1 4/9] cpuidle: teo: Drop local variable prev_intercept_idx
Date: Mon, 13 Jan 2025 19:40:49 +0100 [thread overview]
Message-ID: <3327997.aeNJFYEL58@rjwysocki.net> (raw)
In-Reply-To: <6116275.lOV4Wx5bFT@rjwysocki.net>
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Local variable prev_intercept_idx in teo_select() is redundant becase
it cannot be 0 when candidate state index is 0.
The prev_intercept_idx value is the index of the deepest enabled idle
state, so if it is 0, state 0 is the deepest enabled idle state, in
which case it must be the only enabled idle state, but then teo_select()
would have returned early before initializing prev_intercept_idx.
Thus prev_intercept_idx must be nonzero and the check of it against 0
always passes, so it can be dropped altogether.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/cpuidle/governors/teo.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
--- a/drivers/cpuidle/governors/teo.c
+++ b/drivers/cpuidle/governors/teo.c
@@ -292,7 +292,6 @@
unsigned int hit_sum = 0;
int constraint_idx = 0;
int idx0 = 0, idx = -1;
- int prev_intercept_idx;
s64 duration_ns;
int i;
@@ -370,7 +369,6 @@
* all of the deeper states, a shallower idle state is likely to be a
* better choice.
*/
- prev_intercept_idx = idx;
if (2 * idx_intercept_sum > cpu_data->total - idx_hit_sum) {
int first_suitable_idx = idx;
@@ -437,14 +435,11 @@
idx = constraint_idx;
if (!idx) {
- if (prev_intercept_idx) {
- /*
- * Query the sleep length to be able to count the wakeup
- * as a hit if it is caused by a timer.
- */
- duration_ns = tick_nohz_get_sleep_length(&delta_tick);
- cpu_data->sleep_length_ns = duration_ns;
- }
+ /*
+ * Query the sleep length to be able to count the wakeup as a
+ * hit if it is caused by a timer.
+ */
+ cpu_data->sleep_length_ns = tick_nohz_get_sleep_length(&delta_tick);
goto out_tick;
}
next prev parent reply other threads:[~2025-01-13 18:52 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-13 18:32 [PATCH v1 0/9] cpuidle: teo: Cleanups and very frequent wakeups handling update Rafael J. Wysocki
2025-01-13 18:34 ` [PATCH v1 1/9] cpuidle: teo: Rearrange idle state lookup code Rafael J. Wysocki
2025-01-15 14:21 ` Christian Loehle
2025-01-13 18:36 ` [PATCH v1 2/9] cpuidle: teo: Reorder candidate state index checks Rafael J. Wysocki
2025-01-15 14:46 ` Christian Loehle
2025-01-15 15:54 ` Rafael J. Wysocki
2025-01-15 19:20 ` Christian Loehle
2025-01-15 20:48 ` Rafael J. Wysocki
2025-01-15 21:10 ` Rafael J. Wysocki
2025-01-16 12:22 ` Rafael J. Wysocki
2025-01-16 13:26 ` Christian Loehle
2025-01-16 13:27 ` Christian Loehle
2025-01-13 18:39 ` [PATCH v1 3/9] cpuidle: teo: Combine candidate state index checks against 0 Rafael J. Wysocki
2025-01-15 19:44 ` Christian Loehle
2025-01-13 18:40 ` Rafael J. Wysocki [this message]
2025-01-15 19:46 ` [PATCH v1 4/9] cpuidle: teo: Drop local variable prev_intercept_idx Christian Loehle
2025-01-13 18:41 ` [PATCH v1 5/9] cpuidle: teo: Clarify two code comments Rafael J. Wysocki
2025-01-15 19:43 ` Christian Loehle
2025-01-13 18:45 ` [PATCH v1 6/9] cpuidle: teo: Simplify counting events used for tick management Rafael J. Wysocki
2025-01-20 11:27 ` Christian Loehle
2025-01-13 18:48 ` [PATCH v1 7/9] cpuidle: teo: Skip getting the sleep length is wakeups are very frequent Rafael J. Wysocki
2025-01-20 12:08 ` Christian Loehle
2025-01-20 16:24 ` Rafael J. Wysocki
2025-01-13 18:50 ` [PATCH v1 8/9] cpuidle: teo: Simplify handling of total events count Rafael J. Wysocki
2025-01-20 12:10 ` Christian Loehle
2025-01-13 18:51 ` [PATCH v1 9/9] cpuidle: teo: Replace time_span_ns with a flag Rafael J. Wysocki
2025-01-20 12:16 ` Christian Loehle
2025-01-20 12:42 ` Rafael J. Wysocki
2025-01-15 14:52 ` [PATCH v1 0/9] cpuidle: teo: Cleanups and very frequent wakeups handling update Christian Loehle
2025-01-20 8:17 ` Aboorva Devarajan
2025-01-20 16:26 ` Rafael J. Wysocki
2025-01-20 16:24 ` Rafael J. Wysocki
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