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| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-08-16 23:42:57 -0400 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-08-18 18:13:47 -0400 |
| commit | 1d18538e6a09265003a0a94ca779d7a6127cb76c (patch) | |
| tree | 79c71bb9a4c4ed5a3848bdbb155b6b1dfe8a08a0 /kernel/trace/trace_event_perf.c | |
| parent | 8b0e6c744fef6462382041b30878c91f15069fc6 (diff) | |
| download | lwn-1d18538e6a09265003a0a94ca779d7a6127cb76c.tar.gz lwn-1d18538e6a09265003a0a94ca779d7a6127cb76c.zip | |
tracing: Have dynamic events have a ref counter
As dynamic events are not created by modules, if something is attached to
one, calling "try_module_get()" on its "mod" field, is not going to keep
the dynamic event from going away.
Since dynamic events do not need the "mod" pointer of the event structure,
make a union out of it in order to save memory (there's one structure for
each of the thousand+ events in the kernel), and have any event with the
DYNAMIC flag set to use a ref counter instead.
Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/
Link: https://lkml.kernel.org/r/20210817035027.174869074@goodmis.org
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_event_perf.c')
| -rw-r--r-- | kernel/trace/trace_event_perf.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 03be4435d103..6aed10e2f7ce 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -177,7 +177,7 @@ static void perf_trace_event_unreg(struct perf_event *p_event) } } out: - module_put(tp_event->mod); + trace_event_put_ref(tp_event); } static int perf_trace_event_open(struct perf_event *p_event) @@ -224,10 +224,10 @@ int perf_trace_init(struct perf_event *p_event) list_for_each_entry(tp_event, &ftrace_events, list) { if (tp_event->event.type == event_id && tp_event->class && tp_event->class->reg && - try_module_get(tp_event->mod)) { + trace_event_try_get_ref(tp_event)) { ret = perf_trace_event_init(tp_event, p_event); if (ret) - module_put(tp_event->mod); + trace_event_put_ref(tp_event); break; } } |