From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f177.google.com (mail-pf0-f177.google.com [209.85.192.177]) by dpdk.org (Postfix) with ESMTP id 97FFEB62 for ; Mon, 14 Dec 2015 20:13:03 +0100 (CET) Received: by pfbu66 with SMTP id u66so65702740pfb.3 for ; Mon, 14 Dec 2015 11:13:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:subject:message-id:in-reply-to:references:mime-version :content-type:content-transfer-encoding; bh=Ssnt6gcAliw6/5CGtzv6PV7322mhjOoiAKecF9R+unU=; b=rH6VdORhT4u7TDSuINgH72cV6U2ME7lNz2XHlP5xyLk4tPI510XedQe8JdeRElEI53 E/n0JpPHH81uIdXA6Gx0A+GTu6eTQNQXTdaJoE2BF5qD+tPt7u1mDq0e9tiO71WDMlKR JFWAmLSiPRTAvO+rRdc4SgbifGMmPEnK/GgGNMx+y2Z1q2VDpQmInmXBNcpmHpsbQ4NS QfIa1t4ul2DMjHOzpcAjDP5KcEkmrdM4Us14z9q1WDBItCHnHFhRxKO+IGBFbAvKCgAH YdiBAGzOMDKTFVYQT3Qzn/VASs8/f/8sdsn9oPR0TxnDpr+cVu0Iv7Uv8u8nT6jvi2cL 8Y1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:subject:message-id:in-reply-to :references:mime-version:content-type:content-transfer-encoding; bh=Ssnt6gcAliw6/5CGtzv6PV7322mhjOoiAKecF9R+unU=; b=boFfFADYWeZX1mZesCAav8/iolxLk78LvOT7RSsRog2jwVgEc/21dNasZtndid4gCL 6ba97Zko7Es0o3eJQV1NvP3vMYrWHm96RYfvDkdjNnPDGM8kY4q0AITa7dBo65c2DIaG BBnB5nEYn2Mv2rs2Oz7GKqipSKnyXfK/UBr7rDUX3R+Eu4ZpkJe2jbMXbPSBB4wsJYXo Ouy1b4bA4vFuEXV5iUvL3u8oOJQIGKaOvfPevmqM4CP1VVnQm+9jZWardFOuiwnqYxll o/J3WSLyfJgzzrZUml3kj60GIodkW58bXG9UlFNL9LF/e0Gm3p1I3fUzUC+Xt4F+Rk5I JIsg== X-Gm-Message-State: ALoCoQnJG2u5+V73SasNvFy8IWUUXiBV4jJcS5nZFshFwLQNhRSCFOdVHUsY/HN3Ambgy64QP5vVUSXcMO7q8vidw+so+2kcBg== X-Received: by 10.98.69.216 with SMTP id n85mr21525913pfi.21.1450120382932; Mon, 14 Dec 2015 11:13:02 -0800 (PST) Received: from xeon-e3 (static-50-53-82-155.bvtn.or.frontiernet.net. [50.53.82.155]) by smtp.gmail.com with ESMTPSA id wo3sm44523867pab.25.2015.12.14.11.13.02 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Dec 2015 11:13:02 -0800 (PST) Date: Mon, 14 Dec 2015 11:13:11 -0800 From: Stephen Hemminger To: dev@dpdk.org Message-ID: <20151214111311.37a2e484@xeon-e3> In-Reply-To: <1450117567-12173-1-git-send-email-stephen@networkplumber.org> References: <1450117567-12173-1-git-send-email-stephen@networkplumber.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH] nohz: disable traceback on NO_HZ warning X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Dec 2015 19:13:04 -0000 On Mon, 14 Dec 2015 10:26:07 -0800 Stephen Hemminger wrote: > From: "Charles (Chas) Williams" > > A NO_HZ_FULL kernel needs to have a stable clock source like a non-stop > (or invariant) TSC. Unfortunately, this CPU feature/flag isn't advertised > by most hypervisors because they want the ability to migrate or save > virtual machines which would affect the TSC. > > This means that a kernel with NO_HZ_FULL configured would often generate > a kernel traceback on boot which causes users to generate false > alarms. NO_HZ_FULL is an optimization not a hard requirement. > Keep the message, just lose the traceback. > > Signed-off-by: Charles (Chas) Williams > Signed-off-by: Stephen Hemminger > --- > kernel/time/tick-sched.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c > index 7c7ec45..2e1c90c 100644 > --- a/kernel/time/tick-sched.c > +++ b/kernel/time/tick-sched.c > @@ -188,8 +188,8 @@ static bool can_stop_full_tick(void) > * Don't allow the user to think they can get > * full NO_HZ with this machine. > */ > - WARN_ONCE(tick_nohz_full_running, > - "NO_HZ FULL will not work with unstable sched clock"); > + if (tick_nohz_full_running) > + pr_notice_once("NO_HZ FULL will not work with unstable sched clock\n"); > return false; > } > #endif Never mind, wrong list