Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760295Ab0FQQD2 (ORCPT ); Thu, 17 Jun 2010 12:03:28 -0400 Received: from casper.infradead.org ([85.118.1.10]:49151 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756511Ab0FQQD1 convert rfc822-to-8bit (ORCPT ); Thu, 17 Jun 2010 12:03:27 -0400 Subject: [PATCH] nohz: Fix nohz ratelimit From: Peter Zijlstra To: Brian Bloniarz Cc: Mike Galbraith , Jiri Kosina , Chris Wedgwood , Linus Torvalds , Greg KH , Alan Cox , OGAWA Hirofumi , Jef Driesen , linux-kernel@vger.kernel.org, Ingo Molnar , Thomas Gleixner In-Reply-To: <4C1A378F.7070604@athenacr.com> References: <20100610181042.GA19210@puku.stupidest.org> <4C116652.8010408@athenacr.com> <1276701411.30669.6.camel@marge.simson.net> <1276756770.8248.20.camel@marge.simson.net> <1276758038.9628.1.camel@marge.simson.net> <1276771844.8121.14.camel@marge.simson.net> <1276781044.27822.309.camel@twins> <4C1A378F.7070604@athenacr.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Thu, 17 Jun 2010 18:02:37 +0200 Message-ID: <1276790557.27822.516.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1421 Lines: 41 Chris Wedgwood reports that 39c0cbe (sched: Rate-limit nohz) causes a serial console regression, unresponsiveness, and indeed it does. The below fixes it by not skipping out when the tick has been stopped. Reported-by: Chris Wedgwood Tested-by: Brian Bloniarz Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra --- kernel/time/tick-sched.c | 5 +---- 1 files changed, 1 insertions(+), 4 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 5f171f0..e0707ea 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -315,9 +315,6 @@ void tick_nohz_stop_sched_tick(int inidle) goto end; } - if (nohz_ratelimit(cpu)) - goto end; - ts->idle_calls++; /* Read jiffies and the time when jiffies were updated last */ do { @@ -328,7 +325,7 @@ void tick_nohz_stop_sched_tick(int inidle) } while (read_seqretry(&xtime_lock, seq)); if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) || - arch_needs_cpu(cpu)) { + arch_needs_cpu(cpu) || nohz_ratelimit(cpu)) { next_jiffies = last_jiffies + 1; delta_jiffies = 1; } else { -- 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/