From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758545Ab0DPQYV (ORCPT ); Fri, 16 Apr 2010 12:24:21 -0400 Received: from mail-ww0-f46.google.com ([74.125.82.46]:51678 "EHLO mail-ww0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757007Ab0DPQYU (ORCPT ); Fri, 16 Apr 2010 12:24:20 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=eBebL8w3GlxvZCtpjgkRU82Ml07U9sT0MDrLu7wqiVsvHyVRrABCQV15XYk46SOB4n qr0iGqEJm3nSCuNx9pbsD5BPgZDyBvJmfQ5BFvzVSrscBHRQU5SuktEqubsLBH6DaALf bgd8Onnhlx8T1A3s6qIEKmH8Vz4qZDPBlr2yA= Date: Fri, 16 Apr 2010 18:24:19 +0200 From: Frederic Weisbecker To: Don Zickus Cc: mingo@elte.hu, peterz@infradead.org, gorcunov@gmail.com, aris@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] [watchdog] combine nmi_watchdog and softlockup Message-ID: <20100416162417.GI5162@nowhere> References: <1271366710-17468-1-git-send-email-dzickus@redhat.com> <20100416014712.GC15570@nowhere> <20100416141213.GC15159@redhat.com> <20100416144302.GB5162@nowhere> <20100416150407.GH15159@redhat.com> <20100416153210.GG5162@nowhere> <20100416161401.GI15159@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100416161401.GI15159@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 16, 2010 at 12:14:01PM -0400, Don Zickus wrote: > On Fri, Apr 16, 2010 at 05:32:12PM +0200, Frederic Weisbecker wrote: > > > I'll try to implement this. Any objections if I combined hardlockup and > > > softlockup with per cpu watchdog_warn and have bit masks for HARDLOCKUP > > > and SOFTLOCKUP? I hate to just waste per cpu space for this. > > > > > > > > Hmm, a hardlockup can come in after a softlockup. > > Let me re-explain what I meant. It was meant to do double duty. The > softlockup code only checks the SOFTLOCKUP bit and the hardlockup only > ever checks the HARDLOCKUP bit. > > ie if get_cpu_var(watchdog_warn) && HARDLOCKUP { return; } Ah right. > > > Don't worry too much about memory: usually the more you have cpu, > > the more you have memory :) > > Plus this is debugging code, not something supposed to be enabled > > in production. > > Well depends on your POV. In RHEL we enable both NMI_WATCHDOG and > SOFTLOCKUP on production systems (and we have customers that are > thankful for that :-) ). Ok :)