From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx158.postini.com [74.125.245.158]) by kanga.kvack.org (Postfix) with SMTP id 9698A6B002B for ; Mon, 24 Sep 2012 07:13:53 -0400 (EDT) Received: from /spool/local by e28smtp05.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 24 Sep 2012 16:43:50 +0530 Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8OBDiN038207592 for ; Mon, 24 Sep 2012 16:43:44 +0530 Received: from d28av02.in.ibm.com (loopback [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8OBDhcq022508 for ; Mon, 24 Sep 2012 21:13:44 +1000 Message-ID: <50604047.7000908@linux.vnet.ibm.com> Date: Mon, 24 Sep 2012 16:43:11 +0530 From: "Srivatsa S. Bhat" MIME-Version: 1.0 Subject: Re: divide error: bdi_dirty_limit+0x5a/0x9e References: <20120924102324.GA22303@aftab.osrc.amd.com> <50603829.9050904@linux.vnet.ibm.com> <20120924110554.GC22303@aftab.osrc.amd.com> In-Reply-To: <20120924110554.GC22303@aftab.osrc.amd.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Borislav Petkov Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Fengguang Wu , Jan Kara , Peter Zijlstra , Andrew Morton , Johannes Weiner , Conny Seidel , "Paul E. McKenney" On 09/24/2012 04:35 PM, Borislav Petkov wrote: > On Mon, Sep 24, 2012 at 04:08:33PM +0530, Srivatsa S. Bhat wrote: >> On 09/24/2012 03:53 PM, Borislav Petkov wrote: >>> Hi all, >>> >>> we're able to trigger the oops below when doing CPU hotplug tests. >>> >> >> I hit this problem as well, which I reported here, a few days ago: >> https://lkml.org/lkml/2012/9/13/222 > > Ok, your case shows even more info: > > [ 526.024180] divide error: 0000 [#1] SMP > [ 526.028144] Modules linked in: ipv6 cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf fuse loop dm_mod iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm cdc_ether pcspkr usbnet shpchp pci_hotplug i2c_i801 i2c_core ioatdma mii crc32c_intel serio_raw microcode lpc_ich mfd_core i7core_edac bnx2 dca edac_core tpm_tis tpm sg tpm_bios rtc_cmos button uhci_hcd ehci_hcd usbcore usb_common sd_mod crc_t10dif edd ext3 mbcache jbd fan processor mptsas mptscsih mptbase scsi_transport_sas scsi_mod thermal thermal_sys hwmon > [ 526.028145] CPU 9 > [ 526.028145] Pid: 2235, comm: flush-8:0 Not tainted 3.6.0-rc1-tglx-hotplug-0.0.0.28.36b5ec9-default #1 IBM IBM System x -[7870C4Q]-/68Y8033 > [ 526.028145] RIP: 0010:[] [] bdi_dirty_limit+0x66/0xc0 > [ 526.028145] RSP: 0018:ffff8811530bfcc0 EFLAGS: 00010206 > [ 526.028145] RAX: 0000000000b9877e RBX: 00000000001a8112 RCX: 28f5c28f5c28f5c3 > [ 526.028145] RDX: 0000000000000000 RSI: 0000000000b9877e RDI: 0000000000000000 > > %rax contains something != 0 but %rdi definitely is 0. > Yep.. So I tried putting a BUG_ON(!den) in fprop_fraction_percpu() to catch if we really got the code wrong somehow.. but unfortunately, with that added, I haven't been successful in reproducing the bug :( Regards, Srivatsa S. Bhat -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org