a number of suggestions to make the tracer truly lightweight:
- remove the 'event registration' and callback stuff. It just introduces
unnecessery runtime overhead. Use an include file as a registry of
events instead. This will simplify things greatly. Why do you need a
table of callbacks registered to an event? Nothing in your patches
actually uses it ... Just use one tracing function that copies the
arguments into a per-CPU ringbuffer. It's really just a few lines.
- do not disable interrupts when writing events. I used this method in
a tracer and it works well. Just get an irq-safe index to the trace
ring-buffer and fill it in. [eg. on x86 incl can be used for this
purpose.]
- get rid of p->trace_info and the pending_write_count - it's completely
unnecessery.
- drivers/trace/tracer.c is a complex mess of strange coding style and
#ifdefs, it's not proper Linux kernel code.
it's possible to have lightweight tracing - this patch clearly is not
achieving that goal yet.
Ingo
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This archive was generated by hypermail 2b29 : Mon Sep 23 2002 - 22:00:37 EST