From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Len Brown <len.brown@intel.com>, Zhang Rui <rui.zhang@intel.com>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH] intel_idle: Eliminate redundant static variable
Date: Wed, 24 Jun 2020 16:38:51 +0200 [thread overview]
Message-ID: <1731670.qoJTzjjlrN@kreacher> (raw)
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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>
---
drivers/idle/intel_idle.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
Index: linux-pm/drivers/idle/intel_idle.c
===================================================================
--- linux-pm.orig/drivers/idle/intel_idle.c
+++ linux-pm/drivers/idle/intel_idle.c
@@ -66,8 +66,6 @@ static struct cpuidle_device __percpu *i
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 c
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(unsigne
{
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;
reply other threads:[~2020-06-24 14:38 UTC|newest]
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