linux-kernel - Re: [PATCH 12/32] nohz: Try not to give the timekeeping duty to a cpuset nohz cpu

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: <20110830151704.GV9748@somewhere.redhat.com>
Date:	Tue, 30 Aug 2011 17:17:06 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Anton Blanchard <anton@....ibm.com>,
	Avi Kivity <avi@...hat.com>, Ingo Molnar <mingo@...e.hu>,
	Lai Jiangshan <laijs@...fujitsu.com>,
	"Paul E . McKenney" <paulmck@...ux.vnet.ibm.com>,
	Stephen Hemminger <shemminger@...tta.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Tim Pepper <lnxninja@...ux.vnet.ibm.com>,
	Dimitri Sivanich <sivanich@....com>,
	Paul Menage <paul@...lmenage.org>
Subject: Re: [PATCH 12/32] nohz: Try not to give the timekeeping duty to a
 cpuset nohz cpu

On Mon, Aug 29, 2011 at 04:55:45PM +0200, Peter Zijlstra wrote:
> On Mon, 2011-08-15 at 17:52 +0200, Frederic Weisbecker wrote:
> > Try to give the timekeeing duty to a CPU that doesn't belong
> > to any nohz cpuset when possible, so that we increase the chance
> > for these nohz cpusets to run their CPUs out of periodic tick
> > mode. 
> 
> You and Dmitiri might want to get together:
> 
> lkml.kernel.org/r/20110823195628.GB4533@....com

Right!

There is another missing piece in my patchset. If every non adaptive-nohz
CPUs are sleeping, then none is handling the do_timer duty and adaptive nohz
CPUs run with a stale jiffies and walltime.

I need to handle that.
--
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/