From patchwork Wed Nov 12 06:11:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Viresh Kumar X-Patchwork-Id: 40638 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-wg0-f69.google.com (mail-wg0-f69.google.com [74.125.82.69]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id AF125206A5 for ; Wed, 12 Nov 2014 06:11:21 +0000 (UTC) Received: by mail-wg0-f69.google.com with SMTP id l18sf6191802wgh.4 for ; Tue, 11 Nov 2014 22:11:20 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:delivered-to:mime-version:in-reply-to:references :date:message-id:subject:from:to:cc:sender:precedence:list-id :x-original-sender:x-original-authentication-results:mailing-list :list-post:list-help:list-archive:list-unsubscribe:content-type; bh=bx/oSBNLr3l5Qx9285NGiAd4Q4d8fJZbm+2RQZ00vFA=; b=e07ChMvWwzAqe3NAd1i2Xwxz1OILwBLoaq6808r7qpS9twCUmxOYs48fHj2UNO8XbN sHkWJtn5L49OMtusOFDETIa3EvnJSHp2wnhfOQOZ3ySV5IPJDPX5b23DFYFnWvblf1vE VF4H/G1bNZS8wezQxX287yS21diAFrR4PT/jhDwiDMWs7uVEXCR2BJ1DtfyuggYHshdc r4/rK/1hHt0vgpO0UIlLf6fug0ru0dNhhcfdioOXysnX4QIkvLsT3HbhlFGOJFB+iwya d3sFmgK7h4u5xWX+oGzV4sckaOzpjOKSTLP3TjEI8BNKCA558kQoX2TROj22KLl8vDJV aCDA== X-Gm-Message-State: ALoCoQkjSpn+0y5I4/2tWDRWFnfZtbSf1/3RoI8EuKZAaTw3I/qCAIJNLoZbQxzu3IRrUL8uN+hw X-Received: by 10.152.27.38 with SMTP id q6mr1472445lag.5.1415772680865; Tue, 11 Nov 2014 22:11:20 -0800 (PST) X-BeenThere: patchwork-forward@linaro.org Received: by 10.152.2.130 with SMTP id 2ls193646lau.50.gmail; Tue, 11 Nov 2014 22:11:20 -0800 (PST) X-Received: by 10.152.6.228 with SMTP id e4mr40241227laa.71.1415772680439; Tue, 11 Nov 2014 22:11:20 -0800 (PST) Received: from mail-la0-f46.google.com (mail-la0-f46.google.com. [209.85.215.46]) by mx.google.com with ESMTPS id ww1si33570880lbb.128.2014.11.11.22.11.20 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 11 Nov 2014 22:11:20 -0800 (PST) Received-SPF: pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.215.46 as permitted sender) client-ip=209.85.215.46; Received: by mail-la0-f46.google.com with SMTP id gm9so10675883lab.19 for ; Tue, 11 Nov 2014 22:11:20 -0800 (PST) X-Received: by 10.152.87.100 with SMTP id w4mr39636836laz.27.1415772679979; Tue, 11 Nov 2014 22:11:19 -0800 (PST) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patch@linaro.org Received: by 10.112.184.201 with SMTP id ew9csp376078lbc; Tue, 11 Nov 2014 22:11:19 -0800 (PST) X-Received: by 10.68.250.131 with SMTP id zc3mr44916402pbc.34.1415772678354; Tue, 11 Nov 2014 22:11:18 -0800 (PST) Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id ou2si725880pbb.214.2014.11.11.22.11.17 for ; Tue, 11 Nov 2014 22:11:18 -0800 (PST) Received-SPF: none (google.com: linux-kernel-owner@vger.kernel.org does not designate permitted sender hosts) client-ip=209.132.180.67; Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753487AbaKLGLL (ORCPT + 25 others); Wed, 12 Nov 2014 01:11:11 -0500 Received: from mail-oi0-f50.google.com ([209.85.218.50]:51730 "EHLO mail-oi0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751182AbaKLGLJ (ORCPT ); Wed, 12 Nov 2014 01:11:09 -0500 Received: by mail-oi0-f50.google.com with SMTP id v63so8131757oia.37 for ; Tue, 11 Nov 2014 22:11:09 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.202.48.84 with SMTP id w81mr34537498oiw.30.1415772669084; Tue, 11 Nov 2014 22:11:09 -0800 (PST) Received: by 10.182.233.170 with HTTP; Tue, 11 Nov 2014 22:11:09 -0800 (PST) In-Reply-To: <20141111171526.GC3216@lerouge> References: <20141110153147.GK4901@linux.vnet.ibm.com> <20141111171526.GC3216@lerouge> Date: Wed, 12 Nov 2014 11:41:09 +0530 Message-ID: Subject: Re: Future of NOHZ full/isolation development (was Re: [NOHZ] Remove scheduler_tick_max_deferment) From: Viresh Kumar To: Frederic Weisbecker Cc: Christoph Lameter , "Paul E. McKenney" , Thomas Gleixner , Linux Kernel Mailing List , Gilad Ben-Yossef , Tejun Heo , John Stultz , Mike Frysinger , Minchan Kim , Hakan Akkan , Max Krasnyansky , Hugh Dickins , "H. Peter Anvin" , Ingo Molnar , Peter Zijlstra , Kevin Hilman Sender: linux-kernel-owner@vger.kernel.org Precedence: list List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: viresh.kumar@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.215.46 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , On 11 November 2014 22:45, Frederic Weisbecker wrote: > Here is a summarized list: > > * Unbound workqueues affinity (to housekeeper) > * Unbound timers affinity (to housekeeper) > * 1 Hz residual scheduler tick offlining to housekeeper > * Fix some scheduler accounting that don't even work with 1 Hz: cpu load > accounting, rt_scale, load balancing, etc... > * Lighten the syscall path and get rid of cputime accounting + RCU hooks > for people who want isolation + fast syscalls and faults. > * Work on non-affinable workqueues > * Work on non-affinable timers > * ... + spurious interrupts with NOHZ_FULL on all architectures which break isolation but doesn't get caught with traces. Can be observed with this: --- 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/ diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 481fa54..91d490d 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1244,7 +1244,8 @@ void hrtimer_interrupt(struct clock_event_device *dev) { struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases); ktime_t expires_next, now, entry_time, delta; - int i, retries = 0; + int i, retries = 0, count = 0; + static int total_spurious; BUG_ON(!cpu_base->hres_active); cpu_base->nr_events++; @@ -1304,10 +1305,14 @@ void hrtimer_interrupt(struct clock_event_device *dev) break; } + count++; __run_hrtimer(timer, &basenow); } } + if (!count) + pr_err("____%s: Totalspurious: %d\n", __func__, ++total_spurious); + /* * Store the new expiry value so the migration code can verify * against it.