On Fri, 2013-12-27 at 10:51 -0600, Tom Zanussi wrote: > On Fri, 2013-12-27 at 15:54 +0100, Jean-Jacques Hiblot wrote: > > Hi Tom, Steven, > > > > I'm currently doing some tests with the event triggers > > (git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git > > for-next). > > At the moment I can't use event triggers with probes dynamically > > created (with perf probe or via > > /sys/kernel/debug/tracing/kprobe_events) > > Predefined probes like > > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger are working > > fine. > > Am I missing something ? > > > > No, it's just that kprobes hasn't been hooked up yet to actually invoke > the triggers. > > Let me look at doing that over the weekend... >
OK, I just posted a patch to add trigger invocations to kprobes, which you can also find here: http://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto-contrib/log/?h=tzanussi/kprobes-event-triggers I tested it a bit here, but it could use more, so please let me know how it goes.. Tom > Tom > > > example: > > > > ---------------------------------------------------------------- > > with a predefined probe > > ---------------------------------------------------------------- > > > > prompt> echo 'stacktrace' > > > /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger > > prompt> ls > > prompt> cat /sys/kernel/debug/tracing/trace > > # tracer: nop > > # > > # entries-in-buffer/entries-written: 14/14 #P:1 > > # > > # _-----=> irqs-off > > # / _----=> need-resched > > # | / _---=> hardirq/softirq > > # || / _--=> preempt-depth > > # ||| / delay > > # TASK-PID CPU# |||| TIMESTAMP FUNCTION > > # | | | |||| | | > > ls-971 [000] .... 298.050000: <stack trace> > > => ftrace_raw_event_kmem_alloc > > => kmem_cache_alloc_trace > > => do_execve > > => SyS_execve > > => ret_fast_syscall > > ls-971 [000] .... 298.050000: <stack trace> > > => ftrace_raw_event_kmem_alloc > > => kmem_cache_alloc_trace > > => load_elf_binary > > [...] > > > > ---------------------------------------------------------------- > > with a dynamically defined probe > > ---------------------------------------------------------------- > > > > prompt> perf probe -a in_kmalloc=__kmalloc > > prompt> echo 'stacktrace' > > > /sys/kernel/debug/tracing/events/probe/in_kmalloc/trigger > > prompt> perf record -e probe:in_kmalloc -aR sleep 10& > > [... do something here ...] > > prompt> perf report > > [...] > > # Samples: 24 of event 'probe:in_kmalloc' > > # Event count (approx.): 24 > > # > > # Overhead Command Shared Object Symbol > > # ........ ....... ................. ............. > > # > > 50.00% ls [kernel.kallsyms] [k] __kmalloc > > 12.50% sleep [kernel.kallsyms] [k] __kmalloc > > 12.50% sh [kernel.kallsyms] [k] __kmalloc > > 12.50% perf [kernel.kallsyms] [k] __kmalloc > > 12.50% more [kernel.kallsyms] [k] __kmalloc > > [...] > > > > prompt> cat /sys/kernel/debug/tracing/trace > > # tracer: nop > > # > > # entries-in-buffer/entries-written: 0/0 #P:1 > > # > > # _-----=> irqs-off > > # / _----=> need-resched > > # | / _---=> hardirq/softirq > > # || / _--=> preempt-depth > > # random: nonblocking pool is initialized > > ||| / delay > > # TASK-PID CPU# |||| TIMESTAMP FUNCTION > > # | | | |||| | | > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
