linux-kernel - [RFC GIT PULL] nohz: Posix cpu timers handling on full dynticks

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-next>] [day] [month] [year] [list]

Date:	Thu, 18 Apr 2013 19:23:39 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Ingo Molnar <mingo@...nel.org>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Chris Metcalf <cmetcalf@...era.com>,
	Christoph Lameter <cl@...ux.com>,
	Geoff Levand <geoff@...radead.org>,
	Gilad Ben Yossef <gilad@...yossef.com>,
	Hakan Akkan <hakanakkan@...il.com>,
	Kevin Hilman <khilman@...aro.org>,
	Li Zhong <zhong@...ux.vnet.ibm.com>,
	Oleg Nesterov <oleg@...hat.com>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Paul Gortmaker <paul.gortmaker@...driver.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: [RFC GIT PULL] nohz: Posix cpu timers handling on full dynticks

Ingo,

Please consider the following branch:

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
	timers/nohz-posix-timers

Posix cpu timers, perf events tick and sched clock tick need to be
handled in two parts:

1) When a posix cpu timer is enqueued, a list head in perf rotation list is added
or the sched clock is marked unstable, we need to kick the full dynticks CPUs by way
of IPIs so that they reconsider their tick state.

2) Before a full dynticks CPU decides to stop its tick, check if there are posix cpu timers
in the queue, that perf rotation list isn't empty and that sched clock is stable before
shutting down the tick.

This branch handles the first part (which is the trickiest) for posix cpu timers
and also settles the necessary infrastructure to do the same for perf and sched clock
in further pull requests.

As usual, the approach can be further optimized but it's not yet optimization time.

Thanks.

Frederic Weisbecker (3):
  nohz: New APIs to re-evaluate the tick on full dynticks CPUs
  posix_timers: Defer per process timer stop after timers processing
  posix_timers: Kick full dynticks CPUs when a posix cpu timer is armed

 include/linux/tick.h      |    4 +++
 kernel/posix-cpu-timers.c |   35 ++++++++++++++++++++++++++++--
 kernel/time/Kconfig       |    1 +
 kernel/time/tick-sched.c  |   51 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 88 insertions(+), 3 deletions(-)

-- 
1.7.5.4

--
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/