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Message-ID: <20240604212854.725383717@goodmis.org>
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Date: Tue, 04 Jun 2024 17:28:19 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
 linux-trace-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
 Mark Rutland <mark.rutland@arm.com>,
 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
 Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH 2/5] ftrace: Comment __ftrace_hash_rec_update() and make filter_hash bool
References: <20240604212817.384103202@goodmis.org>
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From: "Steven Rostedt (Google)" <rostedt@goodmis.org>

The function __ftrace_hash_rec_update() parameter "filter_hash" is only
used for true or false (boolean), but is of type int. It already has an
"inc" parameter that is boolean. This is confusing, make "filter_hash"
boolean as well.

While at it, add some documentation to that function especially since it
holds the guts of the filtering logic of ftrace.

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 9dcdefe9d1aa..93c7c5fd4249 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1701,8 +1701,20 @@ static bool skip_record(struct dyn_ftrace *rec)
 		!(rec->flags & FTRACE_FL_ENABLED);
 }
 
+/*
+ * This is the main engine to the ftrace updates.
+ *
+ * It will iterate through all the available ftrace functions
+ * (the ones that ftrace can have callbacks to) and set the flags
+ * to the associated dyn_ftrace records.
+ *
+ * @filter_hash: True if for the filter hash is udpated, false for the
+ *               notrace hash
+ * @inc: True to add this hash, false to remove it (increment the
+ *       recorder counters or decrement them).
+ */
 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
-				     int filter_hash,
+				     bool filter_hash,
 				     bool inc)
 {
 	struct ftrace_hash *hash;
-- 
2.43.0