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Diffstat (limited to 'include/linux/preempt.h')
-rw-r--r--include/linux/preempt.h15
1 files changed, 13 insertions, 2 deletions
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 1424670df161..9aa6358a1a16 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -99,14 +99,21 @@ static __always_inline unsigned char interrupt_context_level(void)
return level;
}
+/*
+ * These macro definitions avoid redundant invocations of preempt_count()
+ * because such invocations would result in redundant loads given that
+ * preempt_count() is commonly implemented with READ_ONCE().
+ */
+
#define nmi_count() (preempt_count() & NMI_MASK)
#define hardirq_count() (preempt_count() & HARDIRQ_MASK)
#ifdef CONFIG_PREEMPT_RT
# define softirq_count() (current->softirq_disable_cnt & SOFTIRQ_MASK)
+# define irq_count() ((preempt_count() & (NMI_MASK | HARDIRQ_MASK)) | softirq_count())
#else
# define softirq_count() (preempt_count() & SOFTIRQ_MASK)
+# define irq_count() (preempt_count() & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_MASK))
#endif
-#define irq_count() (nmi_count() | hardirq_count() | softirq_count())
/*
* Macros to retrieve the current execution context:
@@ -119,7 +126,11 @@ static __always_inline unsigned char interrupt_context_level(void)
#define in_nmi() (nmi_count())
#define in_hardirq() (hardirq_count())
#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
-#define in_task() (!(in_nmi() | in_hardirq() | in_serving_softirq()))
+#ifdef CONFIG_PREEMPT_RT
+# define in_task() (!((preempt_count() & (NMI_MASK | HARDIRQ_MASK)) | in_serving_softirq()))
+#else
+# define in_task() (!(preempt_count() & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET)))
+#endif
/*
* The following macros are deprecated and should not be used in new code: