diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2014-05-07 15:06:14 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2014-05-14 11:37:27 -0400 |
| commit | 19eab4a472cfe4a3ae51cff1711d795e3f9bb564 (patch) | |
| tree | a264bc0d172af2f9c425ba676afd47cce46ecb3d /kernel/trace/ftrace.c | |
| parent | 66209a5bd4825e8890bfb65d48efa8a47c647fea (diff) | |
ftrace: Write in missing comment from a very old commit
Back in 2011 Commit ed926f9b35cda "ftrace: Use counters to enable
functions to trace" changed the way ftrace accounts for enabled
and disabled traced functions. There was a comment started as:
/*
*
*/
But never finished. Well, that's rather useless. I probably forgot
to save the file before committing it. And it passed review from all
this time.
Anyway, better late than never. I updated the comment to express what
is happening in that somewhat complex code.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2c99d1f7caf1..61f39f8b62e1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1552,7 +1552,14 @@ static void __ftrace_hash_rec_update(struct ftrace_ops *ops, in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); /* + * If filter_hash is set, we want to match all functions + * that are in the hash but not in the other hash. * + * If filter_hash is not set, then we are decrementing. + * That means we match anything that is in the hash + * and also in the other_hash. That is, we need to turn + * off functions in the other hash because they are disabled + * by this hash. */ if (filter_hash && in_hash && !in_other_hash) match = 1; |