Messages in this thread | | | Date | Mon, 23 Sep 2002 00:50:04 +0200 (CEST) | From | Ingo Molnar <> | Subject | Re: [PATCH] LTT for 2.5.38 1/9: Core infrastructure |
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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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