Re: bug in sched.c:task_hot()

[Ingo Molnar]

* Chen, Kenneth W <kenneth.w.chen@xxxxxxxxx> wrote:

> Current implementation of task_hot() has a performance bug in it
> that it will cause integer underflow.

> -#define task_hot(p, now, sd) ((now) - (p)->timestamp < (sd)->cache_hot_time)
> +#define task_hot(p, now, sd) ((long long) ((now) - (p)->timestamp)	\
> +				< (long long) (sd)->cache_hot_time)

ah ... nice catch.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

	Ingo
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