tracing: add __event_in_*irq() helpers

Patch series "mm: vmscan: add PID and cgroup ID to vmscan tracepoints", v8.

This patch (of 3):

Some trace events want to expose in their output if they were triggered in
an interrupt or softirq context.  Instead of recording this in the event
structure itself, as this information is stored in the flags portion of
the event header, add helper macros that can be used in the print format:

  TP_printk("val=%d %s", __entry->val, __event_in_irq() ? "(in-irq)" : "")

This will output "(in-irq)" for the event in the trace data if the event
was triggered in hard or soft interrupt context.

Link: https://lkml.kernel.org/r/20260316160908.42727-1-tballasi@linux.microsoft.com
Link: https://lore.kernel.org/all/20251229132942.31a2b583@gandalf.local.home/
Link: https://lkml.kernel.org/r/20260316160908.42727-2-tballasi@linux.microsoft.com
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Thomas Ballasi <tballasi@linux.microsoft.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/trace/stages/stage3_trace_output.h b/include/trace/stages/stage3_trace_output.h
index fce85ea2df1c882ef998bcc69f5728ad820d9412..56ec0c0595b106d1de7589ef48106d4428426730 100644 (file)
--- a/include/trace/stages/stage3_trace_output.h
+++ b/include/trace/stages/stage3_trace_output.h
@@ -150,3 +150,11 @@
 
 #undef __get_buf
 #define __get_buf(len)         trace_seq_acquire(p, (len))
+
+#undef __event_in_hardirq
+#undef __event_in_softirq
+#undef __event_in_irq
+
+#define __event_in_hardirq()   (__entry->ent.flags & TRACE_FLAG_HARDIRQ)
+#define __event_in_softirq()   (__entry->ent.flags & TRACE_FLAG_SOFTIRQ)
+#define __event_in_irq()       (__entry->ent.flags & (TRACE_FLAG_HARDIRQ | TRACE_FLAG_SOFTIRQ))

diff --git a/include/trace/stages/stage7_class_define.h b/include/trace/stages/stage7_class_define.h
index fcd564a590f434648525e02815e7c33477ba8bd5..47008897a7956fab1b4bb38065224e852e94b03d 100644 (file)
--- a/include/trace/stages/stage7_class_define.h
+++ b/include/trace/stages/stage7_class_define.h
@@ -26,6 +26,25 @@
 #undef __print_hex_dump
 #undef __get_buf
 
+#undef __event_in_hardirq
+#undef __event_in_softirq
+#undef __event_in_irq
+
+/*
+ * The TRACE_FLAG_* are enums. Instead of using TRACE_DEFINE_ENUM(),
+ * use their hardcoded values. These values are parsed by user space
+ * tooling elsewhere so they will never change.
+ *
+ * See "enum trace_flag_type" in linux/trace_events.h:
+ *   TRACE_FLAG_HARDIRQ
+ *   TRACE_FLAG_SOFTIRQ
+ */
+
+/* This is what is displayed in the format files */
+#define __event_in_hardirq()   (REC->common_flags & 0x8)
+#define __event_in_softirq()   (REC->common_flags & 0x10)
+#define __event_in_irq()       (REC->common_flags & 0x18)
+
 /*
  * The below is not executed in the kernel. It is only what is
  * displayed in the print format for userspace to parse.