Re: [PATCH] Add per-process flag to control thp

[Rasmus Villemoes]

Alex Thorlton <athorlton@xxxxxxx> writes:

> This patch implements functionality to allow processes to disable the use of
> transparent hugepages through the prctl syscall.

A few comments: 

Is there a reason it shouldn't be possible for a process to un-disable/reenable thp? 

> +static inline int transparent_hugepage_enabled(struct vm_area_struct *vma)
> +{
> +	return !current->thp_disabled & _transparent_hugepage_enabled(vma);
> +}

Should probably be &&.

> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 50d04b9..f084c76 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1406,6 +1406,9 @@ struct task_struct {
>  	unsigned int	sequential_io;
>  	unsigned int	sequential_io_avg;
>  #endif
> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> +	int thp_disabled;
> +#endif
>  };

Is there a reason this needs a whole int in task_struct and not just
a single bit?

Rasmus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/