lkml.org 
[lkml]   [2021]   [Oct]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[for-next][PATCH 19/40] tracing/perf: Add interrupt_context_level() helper
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
\
 
 \ /
  Last update: 2021-10-22 23:09    [W:1.017 / U:0.036 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site