diff options
| author | Ulf Hansson <ulf.hansson@linaro.org> | 2025-03-11 17:08:22 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-03-12 21:14:53 +0100 |
| commit | 0f42194c6b22d687fd53c8aea5413cf976366672 (patch) | |
| tree | 2591af76686dd10a12c86ce2c0c10fc6962ee089 | |
| parent | 13b4f9e126cb55b65430bae7e704cea23c78620c (diff) | |
PM: s2idle: Drop redundant locks when entering s2idle
The calls to cpus_read_lock|unlock() protects us from getting CPUS
hotplugged, while entering suspend-to-idle. However, when s2idle_enter() is
called we should be far beyond the point when CPUs may be hotplugged.
Let's therefore simplify the code and drop the use of the lock.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/20250311160827.1129643-2-ulf.hansson@linaro.org
[ rjw: Rewrote the new comment ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | kernel/power/suspend.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 09f8397bae15..1876abf1be15 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -91,6 +91,12 @@ static void s2idle_enter(void) { trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true); + /* + * The correctness of the code below depends on the number of online + * CPUs being stable, but CPUs cannot be taken offline or put online + * while it is running. + */ + raw_spin_lock_irq(&s2idle_lock); if (pm_wakeup_pending()) goto out; @@ -98,8 +104,6 @@ static void s2idle_enter(void) s2idle_state = S2IDLE_STATE_ENTER; raw_spin_unlock_irq(&s2idle_lock); - cpus_read_lock(); - /* Push all the CPUs into the idle loop. */ wake_up_all_idle_cpus(); /* Make the current CPU wait so it can enter the idle loop too. */ @@ -112,8 +116,6 @@ static void s2idle_enter(void) */ wake_up_all_idle_cpus(); - cpus_read_unlock(); - raw_spin_lock_irq(&s2idle_lock); out: |