From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756750Ab0LJVLz (ORCPT ); Fri, 10 Dec 2010 16:11:55 -0500 Received: from mail-fx0-f43.google.com ([209.85.161.43]:63594 "EHLO mail-fx0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752205Ab0LJVLx (ORCPT ); Fri, 10 Dec 2010 16:11:53 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=esTPuzLJbno7qD+RK30JJu0SQRBmTZjcMRMRFkOyNrrtavW7ybKPyeya2NZKfnSrRd vVs3n1A9WVIU7HunyZLtF5V9mILQBZ6lPkNzTmUbshUVhcQjB5orSXn/4osxI9xHBn68 1zCo+EPnbn4emUlH5Bsxsxoppaqw1BW1vokr0= From: Frederic Weisbecker To: "Paul E. McKenney" Cc: LKML , Frederic Weisbecker , "Paul E . McKenney" , Thomas Gleixner , Peter Zijlstra , Steven Rostedt Subject: [PATCH 0/2 v2] rcu: Fix series of spurious RCU softirqs Date: Fri, 10 Dec 2010 22:11:09 +0100 Message-Id: <1292015471-19227-1-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.3.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Following Lai's idea. An example of such series of spurious softirqs: http://tglx.de/~fweisbec/trace_rcu_softirq.txt In that example, the rcu softirq is raised at every tick during 20 secs (was perhaps more, but the trace snapshot happened during 20 secs). It happens randomly. Ah and it survived several hours of rcutorture (with rcu cpu stall detection). Thanks. Frederic Weisbecker (2): rcu: Stop chasing QS if another CPU did it for us rcu: Keep gpnum and completed fields synchronized kernel/rcutree.c | 17 +++++++++++++++++ 1 files changed, 17 insertions(+), 0 deletions(-) -- 1.7.3.2