From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752434Ab3A2X7U (ORCPT ); Tue, 29 Jan 2013 18:59:20 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:51784 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751681Ab3A2X7S (ORCPT ); Tue, 29 Jan 2013 18:59:18 -0500 Date: Tue, 29 Jan 2013 15:59:17 -0800 From: Andrew Morton To: Don Zickus Cc: Mike Lykov , Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, kirill@shutemov.name Subject: Re: [BUG?] false positive in soft lockup detector while unlzma initramfs on slow cpu Message-Id: <20130129155917.4ee64214.akpm@linux-foundation.org> In-Reply-To: <20130129153348.GR98867@redhat.com> References: <5107D1D3.6040105@yandex.ru> <20130129153348.GR98867@redhat.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 29 Jan 2013 10:33:48 -0500 Don Zickus wrote: > --- a/kernel/watchdog.c > +++ b/kernel/watchdog.c > @@ -79,6 +79,14 @@ static int __init softlockup_panic_setup(char *str) > } > __setup("softlockup_panic=", softlockup_panic_setup); > > +static int __init watchdog_thresh_setup(char *str) > +{ > + watchdog_thresh = simple_strtoul(str, NULL, 0); > + > + return 1; > +} > +__setup("watchdog_thresh=", watchdog_thresh_setup); I wonder if there's some magical way in which we can set any sysctl from the kernel command line. Add sys.vm.min_free_kbytes=42 to the command line, walk the hierarchy late in boot... To address Mike's bug I suggest we poke a touch_softlockup_watchdog() into the appropriate place. Presumably the loop in lib/decompress_unlzma.c:unlzma(). The decompress code makes me cry.