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SubjectRe: [PATCH v4 0/2] fix & prevent the missing preemption disabling
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On 2021/10/26 上午10:42, Steven Rostedt wrote:
> On Tue, 26 Oct 2021 10:09:12 +0800
> 王贇 <yun.wang@linux.alibaba.com> wrote:
>
>> Just a ping, to see if there are any more comments :-P
>
> I guess you missed what went into mainline (and your name found a bug
> in my perl script for importing patches ;-)
>
> https://lore.kernel.org/all/20211019091344.65629198@gandalf.local.home/

Cool~ Missing some chinese font maybe, that's fine :-)

>
> Which means patch 1 needs to change:
>> + /*
>> + * Disable preemption to fulfill the promise.
>> + *
>> + * Don't worry about the bit 0 cases, they indicate
>> + * the disabling behaviour has already been done by
>> + * internal call previously.
>> + */
>> + preempt_disable_notrace();
>> +
>> return bit + 1;
>> }
>>
>> +/*
>> + * Preemption will be enabled (if it was previously enabled).
>> + */
>> static __always_inline void trace_clear_recursion(int bit)
>> {
>> if (!bit)
>> return;
>>
>> + if (bit > 0)
>> + preempt_enable_notrace();
>> +
>
> Where this wont work anymore.
>
> Need to preempt disable and enable always.

Yup, will rebase on the latest changes~

Regards,
Michael Wang

>
> -- Steve
>
>
>> barrier();
>> bit--;
>> trace_recursion_clear(bit);
>> @@ -209,7 +227,7 @@ static __always_inline void trace_clear_recursion(int bit)
>> * tracing recursed in the same context (normal vs interrupt),
>> *

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