Messages in this thread | | | Date | Mon, 11 May 2009 15:28:51 +0800 | From | Xiao Guangrong <> | Subject | Re: [PATCH v3] ftrace: add a tracepoint for __raise_softirq_irqoff() |
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Mathieu Desnoyers wrote: > * Xiao Guangrong (xiaoguangrong@cn.fujitsu.com) wrote: >> From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> >>
>> +#ifdef CONFIG_TRACEPOINTS >> +extern void __raise_softirq_irqoff(unsigned int nr); >> +#else >> #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0) > > Can you put the > trace_irq_softirq_raise(nr); > > directly in the define rather than adding this weird CONFIG_TRACEPOINTS? > (and change the define for a static inline), something like : > > static inline void __raise_softirq_irqoff(unsigned int nr) > { > trace_irq_softirq_raise(nr); > or_softirq_pending(1UL << (nr); > } > > This would ensure we don't add a function call on the > __raise_softirq_irqoff() fast-path. >
We did this in v2, and we think it is better for same reason. But ...
> Beware of circular include dependencies though. The tracepoints are > meant not to have this kind of problems (I try to keep the dependencies > very minimalistic), but I wonder if Steven's TRACE_EVENT is now ok on > this aspect. >
We encount this type of problem in v2. So we move to this version(v3).
> If TRACE_EVENT happens to pose problems with circular header > dependencies, then try moving to the DECLARE_TRACE/DEFINE_TRACE scheme > which has been more thoroughly tested as a first step. >
IMHO, TRACE_EVENT framework is better for its more generic as ingo said, and it also provide ftrace support which means user can view tracepoint information from /debug/tracing/events.
Although this TRACE_EVENT happens to expose problems with circular header dependencies, we should not refuse using TRACE_EVENT, instead we should try to fix it for the whole TRACE_EVENT facility later.
Thanks
> Mathieu >
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