tracing: initcall: Ordered comparison of function pointers

2018-04-26T19:02:46+00:00

Using initcall_t in the __field macro generates the following warning with clang version 6.0: include/trace/events/initcall.h:34:3: warning: ordered comparison of function pointers ('initcall_t' (aka 'int (*)(void)') and 'initcall_t') __field macro expands to __field_ext macro which does is_signed_type check on the type argument. Since initcall_t is defined as a function pointer, using it as the type in the __field macro, leads to an ordered comparison of function pointer warning, inside the check. Using __field_struct macro avoids the issue. Link: http://lkml.kernel.org/r/1524699755-29388-1-git-send-email-rishabhb@codeaurora.org Signed-off-by: Rishabh Bhatnagar [ Added comment to why we are using field_struct() ] Signed-off-by: Steven Rostedt (VMware)

init, tracing: Add initcall trace events

2018-04-06T12:56:54+00:00

Being able to trace the start and stop of initcalls is useful to see where the timings are an issue. There is already an "initcall_debug" parameter, but that can cause a large overhead itself, as the printing of the information may take longer than the initcall functions. Adding in a start and finish trace event around the initcall functions, as well as a trace event that records the level of the initcalls, one can get a much finer measurement of the times and interactions of the initcalls themselves, as trace events are much lighter than printk()s. Suggested-by: Abderrahmane Benbachir Signed-off-by: Steven Rostedt (VMware)

kernel/linux.git/include/trace/events/initcall.h, branch v6.6.132

tracing: initcall: Ordered comparison of function pointers

init, tracing: Add initcall trace events