Messages in this thread Patch in this message | | | Date | Fri, 22 Oct 2021 16:48:15 -0400 | From | Steven Rostedt <> | Subject | [for-next][PATCH 19/40] tracing/perf: Add interrupt_context_level() helper |
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From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Now that there are three different instances of doing the addition trick to the preempt_count() and NMI_MASK, HARDIRQ_MASK and SOFTIRQ_OFFSET macros, it deserves a helper function defined in the preempt.h header.
Add the interrupt_context_level() helper and replace the three instances that do that logic with it.
Link: https://lore.kernel.org/all/20211015142541.4badd8a9@gandalf.local.home/
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> --- include/linux/preempt.h | 21 +++++++++++++++++++++ include/linux/trace_recursion.h | 7 +------ kernel/events/internal.h | 7 +------ kernel/trace/ring_buffer.c | 7 +------ 4 files changed, 24 insertions(+), 18 deletions(-)
diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 4d244e295e85..b32e3dabe28b 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -77,6 +77,27 @@ /* preempt_count() and related functions, depends on PREEMPT_NEED_RESCHED */ #include <asm/preempt.h> +/** + * interrupt_context_level - return interrupt context level + * + * Returns the current interrupt context level. + * 0 - normal context + * 1 - softirq context + * 2 - hardirq context + * 3 - NMI context + */ +static __always_inline unsigned char interrupt_context_level(void) +{ + unsigned long pc = preempt_count(); + unsigned char level = 0; + + level += !!(pc & (NMI_MASK)); + level += !!(pc & (NMI_MASK | HARDIRQ_MASK)); + level += !!(pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET)); + + return level; +} + #define nmi_count() (preempt_count() & NMI_MASK) #define hardirq_count() (preempt_count() & HARDIRQ_MASK) #ifdef CONFIG_PREEMPT_RT diff --git a/include/linux/trace_recursion.h b/include/linux/trace_recursion.h index f6da7a03bff0..1d8cce02c3fb 100644 --- a/include/linux/trace_recursion.h +++ b/include/linux/trace_recursion.h @@ -136,12 +136,7 @@ enum { static __always_inline int trace_get_context_bit(void) { - unsigned long pc = preempt_count(); - unsigned char bit = 0; - - bit += !!(pc & (NMI_MASK)); - bit += !!(pc & (NMI_MASK | HARDIRQ_MASK)); - bit += !!(pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET)); + unsigned char bit = interrupt_context_level(); return TRACE_CTX_NORMAL - bit; } diff --git a/kernel/events/internal.h b/kernel/events/internal.h index 228801e20788..082832738c8f 100644 --- a/kernel/events/internal.h +++ b/kernel/events/internal.h @@ -205,12 +205,7 @@ DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user) static inline int get_recursion_context(int *recursion) { - unsigned int pc = preempt_count(); - unsigned char rctx = 0; - - rctx += !!(pc & (NMI_MASK)); - rctx += !!(pc & (NMI_MASK | HARDIRQ_MASK)); - rctx += !!(pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET)); + unsigned char rctx = interrupt_context_level(); if (recursion[rctx]) return -1; diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 15d4380006e3..f6520d0a4c8c 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3167,12 +3167,7 @@ static __always_inline int trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer) { unsigned int val = cpu_buffer->current_context; - unsigned long pc = preempt_count(); - int bit = 0; - - bit += !!(pc & (NMI_MASK)); - bit += !!(pc & (NMI_MASK | HARDIRQ_MASK)); - bit += !!(pc & (NMI_MASK | HARDIRQ_MASK | SOFTIRQ_OFFSET)); + int bit = interrupt_context_level(); bit = RB_CTX_NORMAL - bit; -- 2.33.0
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