Messages in this thread | | | Date | Fri, 10 Mar 2023 10:44:58 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH] tracing: Make tracepoint lockdep check actually test something |
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On Fri, 10 Mar 2023 17:27:58 +0900 Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> This check has been introduced by commit 3a630178fd5f ("tracing: generate RCU > warnings even when tracepoints are disabled"), and it also added a comment > above this macro. > > * When lockdep is enabled, we make sure to always do the RCU portions of > * the tracepoint code, regardless of whether tracing is on. However, > * don't check if the condition is false, due to interaction with idle > * instrumentation. This lets us find RCU issues triggered with tracepoints > * even when this tracepoint is off. This code has no purpose other than > * poking RCU a bit. > > I think at least the last sentence will be outdated by this fix.
Ah thanks, I forgot to update that part. What about:
* When lockdep is enabled, we make sure to always test if RCU is * "watching" regardless if the tracepoint is enabled or not. Tracepoints * require RCU to be active, and it should always warn at the tracepoint * site if it is not watching, as it will need to be active when the * tracepoint is enabled.
?
-- Steve
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