diff options
Diffstat (limited to 'arch/x86/kernel/tracepoint.c')
-rw-r--r-- | arch/x86/kernel/tracepoint.c | 57 |
1 files changed, 19 insertions, 38 deletions
diff --git a/arch/x86/kernel/tracepoint.c b/arch/x86/kernel/tracepoint.c index 15515132bf0d..c6636d1f60b9 100644 --- a/arch/x86/kernel/tracepoint.c +++ b/arch/x86/kernel/tracepoint.c @@ -4,57 +4,38 @@ * Copyright (C) 2013 Seiji Aguchi <seiji.aguchi@hds.com> * */ -#include <asm/hw_irq.h> -#include <asm/desc.h> +#include <linux/jump_label.h> #include <linux/atomic.h> -atomic_t trace_idt_ctr = ATOMIC_INIT(0); -struct desc_ptr trace_idt_descr = { NR_VECTORS * 16 - 1, - (unsigned long) trace_idt_table }; - -/* No need to be aligned, but done to keep all IDTs defined the same way. */ -gate_desc trace_idt_table[NR_VECTORS] __page_aligned_bss; +#include <asm/hw_irq.h> +#include <asm/desc.h> -static int trace_irq_vector_refcount; -static DEFINE_MUTEX(irq_vector_mutex); +DEFINE_STATIC_KEY_FALSE(trace_pagefault_key); -static void set_trace_idt_ctr(int val) +int trace_pagefault_reg(void) { - atomic_set(&trace_idt_ctr, val); - /* Ensure the trace_idt_ctr is set before sending IPI */ - wmb(); + static_branch_inc(&trace_pagefault_key); + return 0; } -static void switch_idt(void *arg) +void trace_pagefault_unreg(void) { - unsigned long flags; - - local_irq_save(flags); - load_current_idt(); - local_irq_restore(flags); + static_branch_dec(&trace_pagefault_key); } -int trace_irq_vector_regfunc(void) +#ifdef CONFIG_SMP + +DEFINE_STATIC_KEY_FALSE(trace_resched_ipi_key); + +int trace_resched_ipi_reg(void) { - mutex_lock(&irq_vector_mutex); - if (!trace_irq_vector_refcount) { - set_trace_idt_ctr(1); - smp_call_function(switch_idt, NULL, 0); - switch_idt(NULL); - } - trace_irq_vector_refcount++; - mutex_unlock(&irq_vector_mutex); + static_branch_inc(&trace_resched_ipi_key); return 0; } -void trace_irq_vector_unregfunc(void) +void trace_resched_ipi_unreg(void) { - mutex_lock(&irq_vector_mutex); - trace_irq_vector_refcount--; - if (!trace_irq_vector_refcount) { - set_trace_idt_ctr(0); - smp_call_function(switch_idt, NULL, 0); - switch_idt(NULL); - } - mutex_unlock(&irq_vector_mutex); + static_branch_dec(&trace_resched_ipi_key); } + +#endif |