From owner-freebsd-current@FreeBSD.ORG Wed Sep 9 18:51:19 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 78AFD106566B; Wed, 9 Sep 2009 18:51:19 +0000 (UTC) (envelope-from jamesbrandongooch@gmail.com) Received: from mail-ew0-f208.google.com (mail-ew0-f208.google.com [209.85.219.208]) by mx1.freebsd.org (Postfix) with ESMTP id DC0FD8FC2A; Wed, 9 Sep 2009 18:51:18 +0000 (UTC) Received: by ewy4 with SMTP id 4so3031968ewy.36 for ; Wed, 09 Sep 2009 11:51:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=VedFD33rWqfVFULdxITIYXKR50PJg8Z0A6DMkTqb5LI=; b=a+d5qwbeUU/JTvA2Xobmb+ddJw2i6TS9oNdl+0Zg7cavDNRD3odHb+lpLjTltzfSbf MoPtk+89/iYNMjRWHX2cVa96gzOrDUyslgFHEI3jAPWde/9T+oym96W2uaotI/Hoovr/ 38x01Dg+b+6GzvUAiH5f7WY8AWfUie640CCL4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=kpc1gPzzEqCPyq7M1lDy8lz5ezZXOIOQYptLwSnCHUqttobgo1aVzunuHE+EVsBNaD oJgy6fqa7HLfZBwZPxxKrmfjs5OPJcHgjoXVa0iMzRtfJCxa+9ZShO1CJxqwWUKY93RG h7Q91cQa5PkTXz/tn9vSZ6hwP9z/rHCyM6bbw= MIME-Version: 1.0 Received: by 10.211.145.11 with SMTP id x11mr562981ebn.74.1252522277718; Wed, 09 Sep 2009 11:51:17 -0700 (PDT) In-Reply-To: <200909091425.15003.jkim@FreeBSD.org> References: <179b97fb0905301355n2a422e05j665fc3a551ce06f1@mail.gmail.com> <4AA7EAB2.5040403@googlemail.com> <200909091425.15003.jkim@FreeBSD.org> Date: Wed, 9 Sep 2009 13:51:17 -0500 Message-ID: <179b97fb0909091151g502c846fq5070f84381f9efa5@mail.gmail.com> From: Brandon Gooch To: Jung-uk Kim Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: bzeeb+freebsd+lor@zabbadoz.net, Felix Stolba , freebsd-current@freebsd.org Subject: Re: LOR acpi_ibm module X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Sep 2009 18:51:19 -0000 On Wed, Sep 9, 2009 at 1:25 PM, Jung-uk Kim wrote: > On Wednesday 09 September 2009 01:49 pm, Felix Stolba wrote: >> Brandon Gooch schrieb: >> > lock order reversal: >> > =A01st 0xffffffff807cf200 sysctl lock (sysctl lock) @ >> > /usr/src/sys/kern/kern_sysctl.c:1608 >> > =A02nd 0xffffffff80bf1de0 ACPI IBM extras (ACPI IBM extras) @ >> > /usr/src/sys/modules/acpi/acpi_ibm/../../../dev/acpi_support/acpi >> >_ibm.c:481 KDB: stack backtrace: >> > db_trace_self_wrapper() at db_trace_self_wrapper+0x2a >> > _witness_debugger() at _witness_debugger+0x2e >> > witness_checkorder() at witness_checkorder+0x81e >> > _sx_xlock() at _sx_xlock+0x54 >> > acpi_ibm_sysctl() at acpi_ibm_sysctl+0x4f >> > sysctl_root() at sysctl_root+0xe3 >> > userland_sysctl() at userland_sysctl+0x158 >> > __sysctl() at __sysctl+0xaa >> > syscall() at syscall+0x1dd >> > Xfast_syscall() at Xfast_syscall+0xd0 >> > --- syscall (202, FreeBSD ELF64, __sysctl), rip =3D 0x80073769c, >> > rsp =3D 0x7fffffffda58, rbp =3D 0x4 --- >> >> I'm getting the same LOR at boot in 9.0-current (source from 7th of >> september). > > It is generally harmless but really annoying. > > Jung-uk Kim > I haven't been running a kernel with WITNESS (or any debugging) for a couple of weeks, so I forgot about it. Originally, I wondered if this locking problem(?) was causing a strange issue when I invoked a script via devd (a call to a script to handle ACPI events through acpi_ibm.ko), in this case, an ACPI screen brightness function: Occasionally, the screen brightness would not adjust when I used the Fn keys, only to eventually, "pop" all of the requests I sent off of the devd command table, usually with a long delay. If I started devd in foreground mode and watched the command output in the terminal, commands were "pushed" and "popped" immediately; all was well. I was never able to put it all together, and it was only a minor annoyance, after all. -Brandon