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Subject[PATCH 4/6] perf,x86: Update rdpmc_always_available static key to modern api
Date
No changes in refcount semantics -- key init is false; replace

static_key_slow_inc|dec with static_branch_inc|dec
static_key_false with static_branch_unlikely

Added a '_key' suffix to rdpmc_always_available, for better self
documentation.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
arch/x86/events/core.c | 6 +++---
arch/x86/include/asm/mmu_context.h | 5 +++--
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index c5f3d83c04ad..7a987e6c7c35 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -48,7 +48,7 @@ DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
.enabled = 1,
};

-struct static_key rdpmc_always_available = STATIC_KEY_INIT_FALSE;
+DEFINE_STATIC_KEY_FALSE(rdpmc_always_available_key);

u64 __read_mostly hw_cache_event_ids
[PERF_COUNT_HW_CACHE_MAX]
@@ -2206,9 +2206,9 @@ static ssize_t set_attr_rdpmc(struct device *cdev,
* but only root can trigger it, so it's okay.
*/
if (val == 2)
- static_key_slow_inc(&rdpmc_always_available);
+ static_branch_inc(&rdpmc_always_available_key);
else
- static_key_slow_dec(&rdpmc_always_available);
+ static_branch_dec(&rdpmc_always_available_key);
on_each_cpu(refresh_pce, NULL, 1);
}

diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 1de72ce514cd..57e3785d0d26 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -24,11 +24,12 @@ static inline void paravirt_activate_mm(struct mm_struct *prev,
#endif /* !CONFIG_PARAVIRT */

#ifdef CONFIG_PERF_EVENTS
-extern struct static_key rdpmc_always_available;
+
+DECLARE_STATIC_KEY_FALSE(rdpmc_always_available_key);

static inline void load_mm_cr4(struct mm_struct *mm)
{
- if (static_key_false(&rdpmc_always_available) ||
+ if (static_branch_unlikely(&rdpmc_always_available_key) ||
atomic_read(&mm->context.perf_rdpmc_allowed))
cr4_set_bits(X86_CR4_PCE);
else
--
2.13.6
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