linux-kernel - Re: [PATCH 5/6] sched, fair: Make group power more consitent

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: <52119C6B.1090009@linux.vnet.ibm.com>
Date:	Mon, 19 Aug 2013 09:47:47 +0530
From:	Preeti U Murthy <preeti@...ux.vnet.ibm.com>
To:	Peter Zijlstra <peterz@...radead.org>
CC:	Ingo Molnar <mingo@...nel.org>,
	Joonsoo Kim <iamjoonsoo.kim@....com>,
	linux-kernel@...r.kernel.org, Mike Galbraith <efault@....de>,
	Paul Turner <pjt@...gle.com>, Alex Shi <alex.shi@...el.com>,
	Vincent Guittot <vincent.guittot@...aro.org>,
	Morten Rasmussen <morten.rasmussen@....com>,
	Namhyung Kim <namhyung@...nel.org>,
	Joonsoo Kim <js1304@...il.com>
Subject: Re: [PATCH 5/6] sched, fair: Make group power more consitent

Hi Peter,

On 08/16/2013 03:42 PM, Peter Zijlstra wrote:

I have a few comments and clarification to seek.

1. How are you ensuring from this patch that sgs->group_power does not
change over the course of load balancing?

    The only path to update_group_power() where sg->sgp->power gets
updated, is from update_sg_lb_stats(). You are updating sgs->group_power
in update_sg_lb_stats(). Any change to group->sgp->power will get
reflected in sgs->group_power as well right?

2. This point is aside from your patch. In the current implementation,
each time the cpu power gets updated in update_cpu_power(), should not
the power of the sched_groups comprising of that cpu also get updated?
Why wait till the load balancing is done at the sched_domain level of
that group, to update its group power?

Regards
Preeti U Murthy

--
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/