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intel_idle: Eliminate redundant static variable 

The value of the lapic_timer_always_reliable static variable in
the intel_idle driver reflects the boot_cpu_has(X86_FEATURE_ARAT)
value and so it also reflects the static_cpu_has(X86_FEATURE_ARAT)
value.

Hence, the lapic_timer_always_reliable check in intel_idle() is
redundant and apart from this lapic_timer_always_reliable is only
used in two places in which boot_cpu_has(X86_FEATURE_ARAT) can be
used directly.

Eliminate the lapic_timer_always_reliable variable in accordance
with the above observations.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki 2020-06-29 13:58:28 +02:00
parent 9ebcfadb06
commit dab20177b6
1 changed files with 3 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
drivers/idle/intel_idle.c
View File

@ -66,8 +66,6 @@ static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
static unsigned long auto_demotion_disable_flags;
static bool disable_promotion_to_c1e;
static bool lapic_timer_always_reliable;
struct idle_cpu {
struct cpuidle_state *state_table;
@ -142,7 +140,7 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev,
if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
leave_mm(cpu);
if (!static_cpu_has(X86_FEATURE_ARAT) && !lapic_timer_always_reliable) {
if (!static_cpu_has(X86_FEATURE_ARAT)) {
/*
* Switch over to one-shot tick broadcast if the target C-state
* is deeper than C1.
@ -1562,7 +1560,7 @@ static int intel_idle_cpu_online(unsigned int cpu)
{
struct cpuidle_device *dev;
if (!lapic_timer_always_reliable)
if (!boot_cpu_has(X86_FEATURE_ARAT))
tick_broadcast_enable();
/*
@ -1655,16 +1653,13 @@ static int __init intel_idle_init(void)
goto init_driver_fail;
}
if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
lapic_timer_always_reliable = true;
retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
intel_idle_cpu_online, NULL);
if (retval < 0)
goto hp_setup_fail;
pr_debug("Local APIC timer is reliable in %s\n",
lapic_timer_always_reliable ? "all C-states" : "C1");
boot_cpu_has(X86_FEATURE_ARAT) ? "all C-states" : "C1");
return 0;