linux-kernel - Re: [PATCH documentation 1/2] nohz1: Add documentation.

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: <877gjyxmiq.fsf@linaro.org>
Date:	Fri, 19 Apr 2013 14:01:49 -0700
From:	Kevin Hilman <khilman@...aro.org>
To:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Cc:	linux-kernel@...r.kernel.org, mingo@...e.hu, laijs@...fujitsu.com,
	dipankar@...ibm.com, akpm@...ux-foundation.org,
	mathieu.desnoyers@...ymtl.ca, josh@...htriplett.org,
	niv@...ibm.com, tglx@...utronix.de, peterz@...radead.org,
	rostedt@...dmis.org, Valdis.Kletnieks@...edu, dhowells@...hat.com,
	edumazet@...gle.com, darren@...art.com, fweisbec@...il.com,
	sbw@....edu, Borislav Petkov <bp@...en8.de>,
	Arjan van de Ven <arjan@...ux.intel.com>,
	Christoph Lameter <cl@...ux.com>
Subject: Re: [PATCH documentation 1/2] nohz1: Add documentation.

"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com> writes:

> +KNOWN ISSUES

[...]

> +o	Unless all CPUs are idle, at least one CPU must keep the
> +	scheduling-clock interrupt going in order to support accurate
> +	timekeeping.

At least with the implementation I'm using (Frederic's 3.9-nohz1
branch), at least one CPU is forced to stay out of dyntick-idle
*always*, even if all CPUs are idle.

IMO, this is important to list as a known issue since this will have
its own power implications when the system is mostly idle.

Otherwise, document looks great.  

Reviewed-by: Kevin Hilman <khilman@...aro.org>

Kevin

--
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/