linux-kernel - Re: [patch 2/2] sched: Scale the nohz_tracker logic by making it per NUMA node

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]

Date:	Mon, 14 Dec 2009 23:21:23 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	venkatesh.pallipadi@...el.com
Cc:	Gautham R Shenoy <ego@...ibm.com>,
	Vaidyanathan Srinivasan <svaidy@...ux.vnet.ibm.com>,
	Ingo Molnar <mingo@...e.hu>,
	Thomas Gleixner <tglx@...utronix.de>,
	Arjan van de Ven <arjan@...radead.org>,
	linux-kernel@...r.kernel.org,
	Suresh Siddha <suresh.b.siddha@...el.com>
Subject: Re: [patch 2/2] sched: Scale the nohz_tracker logic by making it
 per NUMA node

On Thu, 2009-12-10 at 17:27 -0800, venkatesh.pallipadi@...el.com wrote:
> Having one idle CPU doing the rebalancing for all the idle CPUs in
> nohz mode does not scale well with increasing number of cores and
> sockets. Make the nohz_tracker per NUMA node. This results in multiple
> idle load balancing happening at NUMA node level and idle load balancer
> only does the rebalance domain among all the other nohz CPUs in that
> NUMA node.
> 
> This addresses the below problem with the current nohz ilb logic
> * The lone balancer may end up spending a lot of time doing the
> * balancing on
>   behalf of nohz CPUs, especially with increasing number of sockets and
>   cores in the platform.

If the purpose is to keep sockets idle, doing things per node doesn't
seem like a fine plan, since we're having nodes <= socket machines these
days.



--
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/