On 2021/10/26 下午8:01, Steven Rostedt wrote: > On Tue, 26 Oct 2021 17:48:10 +0800 > 王贇 <yun.wang@xxxxxxxxxxxxxxxxx> wrote: > >>> The two comments should be updated too since Steven removed the "bit == 0" >>> trick. >> >> Could you please give more hint on how will it be correct? >> >> I get the point that bit will no longer be 0, there are only -1 or > 0 now >> so trace_test_and_set_recursion() will disable preemption on bit > 0 and >> trace_clear_recursion() will enabled it since it should only be called when >> bit > 0 (I remember we could use a WARN_ON here now :-P). >> >>> >>>> @@ -178,7 +187,7 @@ static __always_inline void trace_clear_recursion(int bit) >>>> * tracing recursed in the same context (normal vs interrupt), >>>> * >>>> * Returns: -1 if a recursion happened. >>>> - * >= 0 if no recursion >>>> + * > 0 if no recursion. >>>> */ >>>> static __always_inline int ftrace_test_recursion_trylock(unsigned long ip, >>>> unsigned long parent_ip) >>> >>> And this change would not be correct now. >> >> I thought it will no longer return 0 so I change it to > 0, isn't that correct? > > No it is not. I removed the bit + 1 return value, which means it returns the > actual bit now. Which is 0 or more. Ah, the return is bit not val, I must be drunk... My apologize for the stupid comments... I'll send a v6 for this patch only to fix that, please let me know if this is not a good way to fix few lines of comments. Regards, Michael Wang > > -- Steve >
