Messages in this thread | | | Subject | Re: [PATCH v6 1/2] ftrace: disable preemption when recursion locked | From | 王贇 <> | Date | Wed, 27 Oct 2021 11:09:29 +0800 |
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On 2021/10/27 上午10:55, Steven Rostedt wrote: > On Wed, 27 Oct 2021 10:34:13 +0800 > 王贇 <yun.wang@linux.alibaba.com> wrote: > >> +/* >> + * Preemption will be enabled (if it was previously enabled). >> + */ >> static __always_inline void trace_clear_recursion(int bit) >> { >> + WARN_ON_ONCE(bit < 0); > > Can you send a v7 without the WARN_ON. > > This is an extremely hot path, and this will cause noticeable overhead. > > If something were to call this with bit < 0, then it would crash and > burn rather quickly.
I see, if the problem will be notified anyway then it's fine, v7 on the way.
Regards, Michael Wang
> > -- Steve > > >> + >> + preempt_enable_notrace(); >> barrier(); >> trace_recursion_clear(bit); >> }
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