[PATCH v2 27/59] x86/softirq: Move softirq pending next to current task

From: Peter Zijlstra
Date: Fri Sep 02 2022 - 10:28:59 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Another hot variable which is strict per CPU and benefits from
being in the same cache line.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
arch/x86/include/asm/current.h | 1 +
arch/x86/include/asm/hardirq.h | 3 ++-
2 files changed, 3 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/current.h
+++ b/arch/x86/include/asm/current.h
@@ -19,6 +19,7 @@ struct pcpu_hot {
int cpu_number;
unsigned long top_of_stack;
void *hardirq_stack_ptr;
+ u16 softirq_pending;
#ifdef CONFIG_X86_64
bool hardirq_stack_inuse;
#else
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -3,9 +3,9 @@
#define _ASM_X86_HARDIRQ_H

#include <linux/threads.h>
+#include <asm/current.h>

typedef struct {
- u16 __softirq_pending;
#if IS_ENABLED(CONFIG_KVM_INTEL)
u8 kvm_cpu_l1tf_flush_l1d;
#endif
@@ -60,6 +60,7 @@ extern u64 arch_irq_stat_cpu(unsigned in
extern u64 arch_irq_stat(void);
#define arch_irq_stat arch_irq_stat

+#define local_softirq_pending_ref pcpu_hot.softirq_pending

#if IS_ENABLED(CONFIG_KVM_INTEL)
static inline void kvm_set_cpu_l1tf_flush_l1d(void)