Re: [PATCH 2/3] sched/fair: Move hot load_avg into its own cacheline

[Peter Zijlstra]

On Wed, Nov 25, 2015 at 02:09:39PM -0500, Waiman Long wrote:
> +++ b/kernel/sched/sched.h
> @@ -248,7 +248,12 @@ struct task_group {
>  	unsigned long shares;
>  
>  #ifdef	CONFIG_SMP
> -	atomic_long_t load_avg;
> +	/*
> +	 * load_avg can be heavily contended at clock tick time, so put
> +	 * it in its own cacheline separated from the fields above which
> +	 * will also be accessed at each tick.
> +	 */
> +	atomic_long_t load_avg ____cacheline_aligned;

Same as with the other patch; this only works if the structure itself is
cacheline aligned, which I don't think it is.

>  #endif
>  #endif
>  
> -- 
> 1.7.1
> 
--
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/