Merge tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...

[linux-2.6-microblaze.git] / Documentation / trace / histogram.rst

diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst
index f933335..b71e09f 100644 (file)
--- a/Documentation/trace/histogram.rst
+++ b/Documentation/trace/histogram.rst
@@ -1776,6 +1776,24 @@ consisting of the name of the new event along with one or more
 variables and their types, which can be any valid field type,
 separated by semicolons, to the tracing/synthetic_events file.
 
+See synth_field_size() for available types.
+
+If field_name contains [n], the field is considered to be a static array.
+
+If field_names contains[] (no subscript), the field is considered to
+be a dynamic array, which will only take as much space in the event as
+is required to hold the array.
+
+A string field can be specified using either the static notation:
+
+  char name[32];
+
+Or the dynamic:
+
+  char name[];
+
+The size limit for either is 256.
+
 For instance, the following creates a new event named 'wakeup_latency'
 with 3 fields: lat, pid, and prio.  Each of those fields is simply a
 variable reference to a variable on another event::