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Message-ID: <166601844863.401.9155951814716704738.tip-bot2@tip-bot2>
Date: Mon, 17 Oct 2022 14:54:08 -0000
From: "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Thomas Gleixner <tglx@...utronix.de>,
"Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
linux-kernel@...r.kernel.org
Subject: [tip: x86/core] x86/percpu: Move preempt_count next to current_task
The following commit has been merged into the x86/core branch of tip:
Commit-ID: 64701838bf0575ef8acb1ad2db5934e864f3e6c3
Gitweb: https://git.kernel.org/tip/64701838bf0575ef8acb1ad2db5934e864f3e6c3
Author: Thomas Gleixner <tglx@...utronix.de>
AuthorDate: Thu, 15 Sep 2022 13:11:02 +02:00
Committer: Peter Zijlstra <peterz@...radead.org>
CommitterDate: Mon, 17 Oct 2022 16:41:04 +02:00
x86/percpu: Move preempt_count next to current_task
Add preempt_count to pcpu_hot, since it is once of the most used
per-cpu variables.
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Link: https://lore.kernel.org/r/20220915111145.284170644@infradead.org
---
arch/x86/include/asm/current.h | 1 +
arch/x86/include/asm/preempt.h | 27 ++++++++++++++-------------
arch/x86/kernel/cpu/common.c | 8 +-------
3 files changed, 16 insertions(+), 20 deletions(-)
diff --git a/arch/x86/include/asm/current.h b/arch/x86/include/asm/current.h
index 63c42ac..0f4b462 100644
--- a/arch/x86/include/asm/current.h
+++ b/arch/x86/include/asm/current.h
@@ -15,6 +15,7 @@ struct pcpu_hot {
union {
struct {
struct task_struct *current_task;
+ int preempt_count;
};
u8 pad[64];
};
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index 5f6daea..2d13f25 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -4,11 +4,11 @@
#include <asm/rmwcc.h>
#include <asm/percpu.h>
+#include <asm/current.h>
+
#include <linux/thread_info.h>
#include <linux/static_call_types.h>
-DECLARE_PER_CPU(int, __preempt_count);
-
/* We use the MSB mostly because its available */
#define PREEMPT_NEED_RESCHED 0x80000000
@@ -24,7 +24,7 @@ DECLARE_PER_CPU(int, __preempt_count);
*/
static __always_inline int preempt_count(void)
{
- return raw_cpu_read_4(__preempt_count) & ~PREEMPT_NEED_RESCHED;
+ return raw_cpu_read_4(pcpu_hot.preempt_count) & ~PREEMPT_NEED_RESCHED;
}
static __always_inline void preempt_count_set(int pc)
@@ -32,10 +32,10 @@ static __always_inline void preempt_count_set(int pc)
int old, new;
do {
- old = raw_cpu_read_4(__preempt_count);
+ old = raw_cpu_read_4(pcpu_hot.preempt_count);
new = (old & PREEMPT_NEED_RESCHED) |
(pc & ~PREEMPT_NEED_RESCHED);
- } while (raw_cpu_cmpxchg_4(__preempt_count, old, new) != old);
+ } while (raw_cpu_cmpxchg_4(pcpu_hot.preempt_count, old, new) != old);
}
/*
@@ -44,7 +44,7 @@ static __always_inline void preempt_count_set(int pc)
#define init_task_preempt_count(p) do { } while (0)
#define init_idle_preempt_count(p, cpu) do { \
- per_cpu(__preempt_count, (cpu)) = PREEMPT_DISABLED; \
+ per_cpu(pcpu_hot.preempt_count, (cpu)) = PREEMPT_DISABLED; \
} while (0)
/*
@@ -58,17 +58,17 @@ static __always_inline void preempt_count_set(int pc)
static __always_inline void set_preempt_need_resched(void)
{
- raw_cpu_and_4(__preempt_count, ~PREEMPT_NEED_RESCHED);
+ raw_cpu_and_4(pcpu_hot.preempt_count, ~PREEMPT_NEED_RESCHED);
}
static __always_inline void clear_preempt_need_resched(void)
{
- raw_cpu_or_4(__preempt_count, PREEMPT_NEED_RESCHED);
+ raw_cpu_or_4(pcpu_hot.preempt_count, PREEMPT_NEED_RESCHED);
}
static __always_inline bool test_preempt_need_resched(void)
{
- return !(raw_cpu_read_4(__preempt_count) & PREEMPT_NEED_RESCHED);
+ return !(raw_cpu_read_4(pcpu_hot.preempt_count) & PREEMPT_NEED_RESCHED);
}
/*
@@ -77,12 +77,12 @@ static __always_inline bool test_preempt_need_resched(void)
static __always_inline void __preempt_count_add(int val)
{
- raw_cpu_add_4(__preempt_count, val);
+ raw_cpu_add_4(pcpu_hot.preempt_count, val);
}
static __always_inline void __preempt_count_sub(int val)
{
- raw_cpu_add_4(__preempt_count, -val);
+ raw_cpu_add_4(pcpu_hot.preempt_count, -val);
}
/*
@@ -92,7 +92,8 @@ static __always_inline void __preempt_count_sub(int val)
*/
static __always_inline bool __preempt_count_dec_and_test(void)
{
- return GEN_UNARY_RMWcc("decl", __preempt_count, e, __percpu_arg([var]));
+ return GEN_UNARY_RMWcc("decl", pcpu_hot.preempt_count, e,
+ __percpu_arg([var]));
}
/*
@@ -100,7 +101,7 @@ static __always_inline bool __preempt_count_dec_and_test(void)
*/
static __always_inline bool should_resched(int preempt_offset)
{
- return unlikely(raw_cpu_read_4(__preempt_count) == preempt_offset);
+ return unlikely(raw_cpu_read_4(pcpu_hot.preempt_count) == preempt_offset);
}
#ifdef CONFIG_PREEMPTION
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 5207153..cafb6bd 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2014,6 +2014,7 @@ __setup("clearcpuid=", setup_clearcpuid);
DEFINE_PER_CPU_ALIGNED(struct pcpu_hot, pcpu_hot) = {
.current_task = &init_task,
+ .preempt_count = INIT_PREEMPT_COUNT,
};
EXPORT_PER_CPU_SYMBOL(pcpu_hot);
@@ -2022,13 +2023,9 @@ DEFINE_PER_CPU_FIRST(struct fixed_percpu_data,
fixed_percpu_data) __aligned(PAGE_SIZE) __visible;
EXPORT_PER_CPU_SYMBOL_GPL(fixed_percpu_data);
-
DEFINE_PER_CPU(void *, hardirq_stack_ptr);
DEFINE_PER_CPU(bool, hardirq_stack_inuse);
-DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
-EXPORT_PER_CPU_SYMBOL(__preempt_count);
-
DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) = TOP_OF_INIT_STACK;
static void wrmsrl_cstar(unsigned long val)
@@ -2081,9 +2078,6 @@ void syscall_init(void)
#else /* CONFIG_X86_64 */
-DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
-EXPORT_PER_CPU_SYMBOL(__preempt_count);
-
/*
* On x86_32, vm86 modifies tss.sp0, so sp0 isn't a reliable way to find
* the top of the kernel stack. Use an extra percpu variable to track the
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