Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752411Ab3JSPR1 (ORCPT ); Sat, 19 Oct 2013 11:17:27 -0400 Received: from mail-wi0-f174.google.com ([209.85.212.174]:61872 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750901Ab3JSPR0 (ORCPT ); Sat, 19 Oct 2013 11:17:26 -0400 From: Frederic Weisbecker To: Oleg Nesterov , Peter Zijlstra Cc: LKML , Frederic Weisbecker , Fernando Luis Vazquez Cao , Tetsuo Handa , Thomas Gleixner , Ingo Molnar , Andrew Morton , Arjan van de Ven Subject: [RFC PATCH 0/5] nohz: Fix racy sleeptime stats v2 Date: Sat, 19 Oct 2013 17:17:16 +0200 Message-Id: <1382195841-6558-1-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1883 Lines: 49 Hi, So this is a new iteration with some more changes on top of the latest discussions we had. Unfortunately it's not yet a real viable solution. Check out patch 4/5 for details, I think that's too much overhead. Also it changes enough the semantics to break the idle sleeptime accounting along the way. This is because moving the accounting to io_schedule() makes it account _all_ IO sleeptime, even if the CPU is still busy, not just when it is idle like before. As a result, the idle sleeptime, that relies on a diff against the io sleeptime, is broken. Anyway, my hope with this new take is mostly to launch a discussion with a fresher base and see if we can find better ideas. Thanks! git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git sched/iowait Thanks, Frederic --- Frederic Weisbecker (5): nohz: Convert a few places to use local per cpu accesses nohz: Only update sleeptime stats locally timer: Change idle/iowait accounting semantics sched: Refactor iowait accounting nohz: Synchronize sleep time stats with seqlock include/linux/ktime.h | 7 +++ include/linux/sched.h | 1 + include/linux/tick.h | 11 ++-- kernel/sched/core.c | 68 ++++++++++++++++++--- kernel/sched/cputime.c | 2 +- kernel/sched/sched.h | 5 +- kernel/softirq.c | 4 +- kernel/time/tick-broadcast.c | 6 +- kernel/time/tick-internal.h | 4 +- kernel/time/tick-sched.c | 138 ++++++++++++++----------------------------- kernel/time/timer_list.c | 3 +- 11 files changed, 130 insertions(+), 119 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/