From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 13 May 2002 12:18:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 13 May 2002 12:18:12 -0400 Received: from gateway-1237.mvista.com ([12.44.186.158]:29181 "EHLO hermes.mvista.com") by vger.kernel.org with ESMTP id ; Mon, 13 May 2002 12:18:10 -0400 Subject: Re: error : preempt_count 1 From: Robert Love To: Oliver Kowalke Cc: linux-kernel@vger.kernel.org In-Reply-To: <1779HB-01zk0WC@fwd06.sul.t-online.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.3 (1.0.3-6) Date: 13 May 2002 09:18:07 -0700 Message-Id: <1021306688.18799.2564.camel@summit> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2002-05-12 at 23:25, Oliver Kowalke wrote: > after shutdown (kernel 2.5.15) I've got : > > erro: halt[8635] exited with preempt_count 1 > > What does it mean? Absolutely nothing bad. It is a debugging check to catch bad code that does funny things with locks. Ideally, every program should call unlock for each instance it called lock - balancing everything out and giving a preempt_count of zero. Some code in the kernel, knowing it is shutting down, does not bother to drop any held locks and subsequently you see that message. Since it is triggering false positives, I will remove it eventually. For now it is incredibly useful for catching real problems. And the above, while harmless, could be fixed for "cleanliness" concerns. Robert Love