Messages in this thread | | | Date | Sat, 25 Oct 2008 09:50:05 -0400 (EDT) | From | Steven Rostedt <> | Subject | Re: [PATCH][RFC] ftrace: function oprofiler |
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On Sat, 25 Oct 2008, Fr?d?ric Weisbecker wrote:
> Hi Steven, > > 2008/10/25 Steven Rostedt <rostedt@goodmis.org>: > > # cat /debug/tracing/ftrace_profile | sort -brn | head -20 > > 280075 : __rcu_read_unlock+0xb/0xa2 > > 280065 : __rcu_read_lock+0x11/0xb3 > > The rcu function are on top of this profile. May be it's because you use > rcu when you touch your hash table. > Wouldn't be interesting to disable the counter adding for these > functions when they > are used at this time?
It is disabled at that time. Look at the trace_active variable. If it is already set for that CPU, the counter is disabled.
But! That said. I need to make the count an atomic inc. There's nothing protecting it from SMP.
> > > +config FUNCTION_PROFILER > > + bool "Trace max stack" > > Copy-paste error? :-)
Hehe, yeah. This and the above bug are both the cause of writing this after midnight. That is exactly why I said this is not ready for inclusion ;-)
-- Steve
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