Re: [patch V4 part 1 14/36] x86/entry: Get rid of ist_begin/end_non_atomic()

Thomas Gleixner
2020-05-15T09:35:28Z

Mathieu Desnoyers <mathieu.desnoyers@efficios.com> writes:

> ----- On May 5, 2020, at 9:16 AM, Thomas Gleixner tglx@linutronix.de wrote:
>
>> This is completely overengineered and definitely not an interface which
>> should be made available to anything else than this particular MCE case.
>
> This patch introduces a significant change under the radar (not explained
> in the changelog): it turns preempt_enable_no_resched() into preempt_enable().
>
> Why, and why was it a no_resched() in the first place ? Was it for performance
> or correctness reasons ?

_no_resched() is an optimization when in code which cannot schedule
anyway. But #MC is definitely not a performance critical hotpath.

So yes, it's a change but really not significant.

>> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>> ---
< Remove useless gunk >

Can you please trim your replies?

Thanks,

tglx