On 9/25/20 11:12 PM, Steven Rostedt wrote:
From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx> As tracepoints are discouraged from being added in a header because it can cause side effects if other tracepoints are in headers, as well as bloat the kernel as the trace_<tracepoint>() function is not a small inline, the common workaround is to add a function call that calls a wrapper function in a C file that then calls the tracepoint. But as function calls add overhead, this function should only be called when the tracepoint in question is enabled. To get around this overhead, a static_branch can be used to only have the tracepoint wrapper get called when the tracepoint is enabled. Add a tracepoint_enabled(tp) macro that gets passed the name of the tracepoint, and this becomes a static_branch that is enabled when the tracepoint is enabled and is a nop when the tracepoint is disabled. Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Nice! I'm late here, but you mentioned a v3, so FWIW: Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
