linux-kernel - Re: [PATCH v2 11/11] sched: replace capacity by activity

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: <20140529140204.GH11074@laptop.programming.kicks-ass.net>
Date:	Thu, 29 May 2014 16:02:04 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Vincent Guittot <vincent.guittot@...aro.org>
Cc:	mingo@...nel.org, linux-kernel@...r.kernel.org,
	linux@....linux.org.uk, linux-arm-kernel@...ts.infradead.org,
	preeti@...ux.vnet.ibm.com, Morten.Rasmussen@....com, efault@....de,
	nicolas.pitre@...aro.org, linaro-kernel@...ts.linaro.org,
	daniel.lezcano@...aro.org
Subject: Re: [PATCH v2 11/11] sched: replace capacity by activity

On Fri, May 23, 2014 at 05:53:05PM +0200, Vincent Guittot wrote:
> @@ -6052,8 +6006,8 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
>  		 * with a large weight task outweighs the tasks on the system).
>  		 */
>  		if (prefer_sibling && sds->local &&
> -		    sds->local_stat.group_has_capacity)
> -			sgs->group_capacity = min(sgs->group_capacity, 1U);
> +		    sds->local_stat.group_capacity > 0)
> +			sgs->group_capacity = min(sgs->group_capacity, 1L);
>  
>  		if (update_sd_pick_busiest(env, sds, sg, sgs)) {
>  			sds->busiest = sg;
> @@ -6228,7 +6182,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
>  		 * have to drop below capacity to reach cpu-load equilibrium.
>  		 */
>  		load_above_capacity =
> -			(busiest->sum_nr_running - busiest->group_capacity);
> +			(busiest->sum_nr_running - busiest->group_weight);
>  
>  		load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_POWER_SCALE);
>  		load_above_capacity /= busiest->group_power;

I think you just broke PREFER_SIBLING here..

So we want PREFER_SIBLING to work on nr_running, not utilization because
we want to spread single tasks around, regardless of their utilization.

--
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/