From 380995fde5f36a9d4e2eb3dfb8e409b71fe0e421 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Wed, 16 May 2018 09:37:39 +0100
Subject: [PATCH] sources/perf: Add a comment explaining sp-perf-counter
 structs.

---
 lib/sources/sp-perf-counter.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/sources/sp-perf-counter.h b/lib/sources/sp-perf-counter.h
index c97eb0c8..213aff3c 100644
--- a/lib/sources/sp-perf-counter.h
+++ b/lib/sources/sp-perf-counter.h
@@ -25,6 +25,14 @@
 
 G_BEGIN_DECLS
 
+/* Structs representing the layouts of perf records returned by the
+ * kernel.
+ *
+ * perf returns variable-layout structs based on the
+ * perf_event_sample_format selectors in perf_event_attr.sample_type.
+ * These structs are the particular layouts that sysprof requests.
+ */
+
 #define SP_TYPE_PERF_COUNTER (sp_perf_counter_get_type())
 
 typedef struct _SpPerfCounter SpPerfCounter;