linux-kernel - Re: [PATCH] DLS: add dl_time_equal helper in deadline scheduler

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4F8290F8.90706@gmail.com>
Date:	Mon, 09 Apr 2012 09:34:16 +0200
From:	Juri Lelli <juri.lelli@...il.com>
To:	Hillf Danton <dhillf@...il.com>
CC:	Dario Faggioli <raistlin@...ux.it>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] DLS: add dl_time_equal helper in deadline scheduler

Hi,

On 04/07/2012 09:49 AM, Hillf Danton wrote:
> Hi all
>
> A tiny helper, dl_time_equal, is added for easing readers.
>
> And dl_entity_preempt is redefined to be bool, and its comment is also changed.
>
> Signed-off-by: Hillf Danton<dhillf@...il.com>
> ---
>
> --- a/kernel/sched_dl.c	Sat Apr  7 15:00:28 2012
> +++ b/kernel/sched_dl.c	Sat Apr  7 15:20:10 2012
> @@ -16,16 +16,21 @@
>    */
>   static const struct sched_class dl_sched_class;
>
> -static inline int dl_time_before(u64 a, u64 b)
> +static inline bool dl_time_equal(u64 a, u64 b)
> +{
> +	return a == b;
> +}
> +
> +static inline bool dl_time_before(u64 a, u64 b)
>   {
>   	return (s64)(a - b)<  0;
>   }
>
>   /*
> - * Tells if entity @a should preempt entity @b.
> + * Return true if entity @a could preempt entity @b in term of deadline
>    */
> -static inline
> -int dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
> +static inline bool
> +dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
>   {
>   	return dl_time_before(a->deadline, b->deadline);
>   }
> @@ -885,7 +890,7 @@ static void check_preempt_curr_dl(struct
>   	 * In the unlikely case current and p have the same deadline
>   	 * let us try to decide what's the best thing to do...
>   	 */
> -	if ((s64)(p->dl.deadline - rq->curr->dl.deadline) == 0&&
> +	if (dl_time_equal(p->dl.deadline, rq->curr->dl.deadline)&&
>   	!need_resched())
>   		check_preempt_equal_dl(rq, p);
>   #endif /* CONFIG_SMP */
> --

I'll change the comparison to be deadline_a == deadline_b, but I don't see the
need for a special helper function. It is used only once, better to have the
comparison really inline (a very special case).

Thanks and Regards,

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