From mboxrd@z Thu Jan 1 00:00:00 1970 From: "John Kacur" Subject: Re: [PATCH] Fix Bug messages Date: Thu, 31 Jul 2008 12:13:24 +0200 Message-ID: <520f0cf10807310313q45599221q3db1b6fd7e7c722f@mail.gmail.com> References: <200807301101.32417.j.mell@t-online.de> <20080730171842.GB3420@linux.vnet.ibm.com> <20080731100023.0221ec2b@bull.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_3146_33459054.1217499204794" Cc: "Chirag Jog" , "J?rgen Mell" , "Thomas Gleixner" , LKML , rt-users , "Steven Rostedt" , "Clark Williams" , "Peter Zijlstra" , "Josh Triplett" , "Timothy R. Chavez" To: "Sebastien Dugue" Return-path: Received: from nf-out-0910.google.com ([64.233.182.187]:55523 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755079AbYGaKN0 (ORCPT ); Thu, 31 Jul 2008 06:13:26 -0400 Received: by nf-out-0910.google.com with SMTP id d3so193088nfc.21 for ; Thu, 31 Jul 2008 03:13:24 -0700 (PDT) In-Reply-To: <20080731100023.0221ec2b@bull.net> Sender: linux-rt-users-owner@vger.kernel.org List-ID: ------=_Part_3146_33459054.1217499204794 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Thu, Jul 31, 2008 at 10:00 AM, Sebastien Dugue wrote: > On Wed, 30 Jul 2008 22:48:42 +0530 Chirag Jog = wrote: > >> * J?rgen Mell [2008-07-30 11:01:32]: >> >> > Hello Thomas, >> > >> > On Wednesday, 30. July 2008, Thomas Gleixner wrote: >> > > We are pleased to announce the 2.6.26-rt1 tree, which can be >> > > downloaded from the location: >> > >> > I have tried the new kernel and have some good news and some bad news: >> > >> > The good news: The machine boots and seems to run without major proble= ms. >> > >> > The bad news: It produces continuously lots of bug messages in the err= or >> > logs (cf. attached dmesg.tgz). The error at rtmutex.c:743 was already >> > present in 2.6.25-rt* when ACPI was enabled. The 'using smp_processor_= id >> > () in preemptible code' is new here with 2.6.26. >> > >> > Machine is an old Athlon XP (single core) on an EPOX mainboard with VI= A >> > chipset. >> > >> > If I can help with testing, please let me know. >> > >> > Bye, >> > J=FCrgen >> > >> > >> This patch should solve some of the bug messages. >> It does two things: >> 1. Change rt_runtime_lock to be a raw spinlock as the comment above it >> says: it is nested inside the rq lock. >> >> 2. Change mnt_writers to be a per_cpu locked variable. >> This eliminates the need for the codepath to disable preemption and >> then potentially sleep, leading to the BUG messages >> >> Signed-Off-By: Chirag > > Neat, the only remaining BUGs I see are from sock_prot_inuse_add() > > BUG: using smp_processor_id() in preemptible [00000000] code: arping/1916 > caller is .sock_prot_inuse_add+0x30/0x80 > Call Trace: > [c0000000eed2f910] [c000000000010304] .show_stack+0x70/0x1bc (unreliable) > [c0000000eed2f9c0] [c0000000001a2340] .debug_smp_processor_id+0x138/0x168 > [c0000000eed2fa70] [c0000000002181f4] .sock_prot_inuse_add+0x30/0x80 > [c0000000eed2fb10] [c00000000026d96c] .udp_lib_get_port+0x2a8/0x320 > [c0000000eed2fbc0] [c000000000275b30] .inet_bind+0x168/0x248 > [c0000000eed2fc60] [c000000000215024] .sys_bind+0x98/0xdc > [c0000000eed2fd90] [c0000000002370bc] .compat_sys_socketcall+0xcc/0x214 > [c0000000eed2fe30] [c0000000000086ac] syscall_exit+0x0/0x40 > BUG: arping:1916 task might have lost a preemption check! > Call Trace: > [c0000000eed2f890] [c000000000010304] .show_stack+0x70/0x1bc (unreliable) > [c0000000eed2f940] [c00000000004e298] .preempt_enable_no_resched+0x60/0x7= 8 > [c0000000eed2f9c0] [c0000000001a2348] .debug_smp_processor_id+0x140/0x168 > [c0000000eed2fa70] [c0000000002181f4] .sock_prot_inuse_add+0x30/0x80 > [c0000000eed2fb10] [c00000000026d96c] .udp_lib_get_port+0x2a8/0x320 > [c0000000eed2fbc0] [c000000000275b30] .inet_bind+0x168/0x248 > [c0000000eed2fc60] [c000000000215024] .sys_bind+0x98/0xdc > [c0000000eed2fd90] [c0000000002370bc] .compat_sys_socketcall+0xcc/0x214 > [c0000000eed2fe30] [c0000000000086ac] syscall_exit+0x0/0x40 > Does this simple fix do the trick for you? ------=_Part_3146_33459054.1217499204794 Content-Type: text/x-patch; name=sock_prot_inuse_add-fix.patch Content-Transfer-Encoding: base64 X-Attachment-Id: f_fjb7ja1q0 Content-Disposition: attachment; filename=sock_prot_inuse_add-fix.patch U2lnbmVkLW9mZi1ieTogSm9obiBLYWN1ciA8amthY3VyQGdtYWlsLmNvbT4KCkluZGV4OiBsaW51 eC0yLjYuMjYtcnQxL25ldC9jb3JlL3NvY2suYwo9PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09Ci0tLSBsaW51eC0yLjYuMjYt cnQxLm9yaWcvbmV0L2NvcmUvc29jay5jCisrKyBsaW51eC0yLjYuMjYtcnQxL25ldC9jb3JlL3Nv Y2suYwpAQCAtMTk0Myw3ICsxOTQzLDcgQEAgc3RhdGljIERFQ0xBUkVfQklUTUFQKHByb3RvX2lu dXNlX2lkeCwgUAogI2lmZGVmIENPTkZJR19ORVRfTlMKIHZvaWQgc29ja19wcm90X2ludXNlX2Fk ZChzdHJ1Y3QgbmV0ICpuZXQsIHN0cnVjdCBwcm90byAqcHJvdCwgaW50IHZhbCkKIHsKLQlpbnQg Y3B1ID0gc21wX3Byb2Nlc3Nvcl9pZCgpOworCWludCBjcHUgPSByYXdfc21wX3Byb2Nlc3Nvcl9p ZCgpOwogCXBlcl9jcHVfcHRyKG5ldC0+Y29yZS5pbnVzZSwgY3B1KS0+dmFsW3Byb3QtPmludXNl X2lkeF0gKz0gdmFsOwogfQogRVhQT1JUX1NZTUJPTF9HUEwoc29ja19wcm90X2ludXNlX2FkZCk7 Cg== ------=_Part_3146_33459054.1217499204794--