Messages in this thread | | | Date | Tue, 03 Nov 2009 14:32:30 +0100 | From | Michal Simek <> | Subject | Ftrace for Microblaze - notrace |
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Hi Thomas, Ingo, Steven and others
I am working on ftrace support for Microblaze. I have done basic ftrace support - initcall, kmemtrace and other. Currently I am working on function trace support. I did asm code as is written in Documentation/trace/ftrace-design.txt.
I have two poins/questions.
I desided to use HAVE_FUNCTION_TRACE_MCOUNT_TEST - just test function_trace_stop in asm code - that shouldn't be a problem.
I disable -pg in main Makefile because not work for me (more info below) and I enable it just for two file in arch/microblaze (irq.c and intc.c) - recompile kernel and test. Log is below and you can see that I am able to see output for function. That's why I think that my mcount function should be correct. Am I right?
uclinux login: root Password: # cd ; mkdir /debug; mount -t debugfs none /debug; cat /debug/tracing/available_ tracers; echo function > /debug/tracing/current_tracer;echo 1 > /debug/tracing/t racing_enabled;cat /debug/tracing/trace | head -n 10 wakeup_rt wakeup function sched_switch nop # tracer: function # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | sh-52 [000] 184.940000: irq_call <-do_IRQ sh-52 [000] 184.940000: do_IRQ <-get_irq sh-52 [000] 184.940000: handle_level_irq <-intc_mask_ack sh-52 [000] 184.950000: handle_level_irq <-intc_enable_or_unmask sh-52 [000] 184.950000: do_IRQ <-get_irq sh-52 [000] 184.950000: handle_level_irq <-intc_mask_ack #
When is used -pg flag kernel stops when I enable function tracer. Interesting is that freeze than I setup function tracing (echo function > .../current/tracer). Is it correct behavior? I think that trace should start after (echo 1> .../tracing_enabled).
The next thing is about annotation notrace. I look at all arch. Is there any algorithm which function should use it? I think that this could be a reason why I my kernel freeze when enable function tracer.
I tested to add -pg flag for process.c file and after it kernel freeze too. Is it mean that problem could be there?
Any other suggestion?
Thanks for your help, Michal
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