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  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Wed, 05 Jun 2013 12:42:43 +0800
From:	Michael Wang <wangyun@...ux.vnet.ibm.com>
To:	Viresh Kumar <viresh.kumar@...aro.org>
CC:	mingo@...hat.com, peterz@...radead.org,
	linaro-kernel@...ts.linaro.org, patches@...aro.org,
	linux-kernel@...r.kernel.org, robin.randhawa@....com,
	Steve.Bannister@....com, Liviu.Dudau@....com,
	charles.garcia-tobin@....com, arvind.chauhan@....com
Subject: Re: [PATCH 1/2] sched: Optimize build_sched_domains() for saving
 first SD node for a cpu

Hi, Viresh

On 06/04/2013 07:20 PM, Viresh Kumar wrote:
[snip]
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 58453b8..638f6cb 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -6533,16 +6533,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
>  		sd = NULL;
>  		for (tl = sched_domain_topology; tl->init; tl++) {
>  			sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
> +			if (!*per_cpu_ptr(d.sd, i))

What about:
			if (tl == sched_domain_topology)

It cost less than per_cpu_ptr(), isn't it?

Regards,
Michael Wang

> +				*per_cpu_ptr(d.sd, i) = sd;
>  			if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
>  				sd->flags |= SD_OVERLAP;
>  			if (cpumask_equal(cpu_map, sched_domain_span(sd)))
>  				break;
>  		}
> -
> -		while (sd->child)
> -			sd = sd->child;
> -
> -		*per_cpu_ptr(d.sd, i) = sd;
>  	}
> 
>  	/* Build the groups for the domains */
> 

--
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/

Powered by blists - more mailing lists