From mboxrd@z Thu Jan 1 00:00:00 1970 From: david ahern Subject: Re: soft lockup in kvm_flush_remote_tlbs Date: Wed, 24 Oct 2007 22:26:04 -0600 Message-ID: <47201ADC.2030506@cisco.com> References: <471FCEA6.6000903@cisco.com> <471FD204.6040400@bull.net> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Laurent Vivier Return-path: In-Reply-To: <471FD204.6040400-6ktuUTfB/bM@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org I saw that in the latest git tree, but RHEL5 kernel does not have that func= tion. I guess I'll have to evaluate my options -- upgrading kernels, or bac= kporting code. thanks, david Laurent Vivier wrote: > david ahern a =E9crit : >> I am trying, unsuccessfully so far, to get a vm running with 4 cpus. >> It is failing with a soft lockup: >> >> BUG: soft lockup detected on CPU#3! >> [] softlockup_tick+0x98/0xa6 >> [] update_process_times+0x39/0x5c >> [] smp_apic_timer_interrupt+0x5c/0x64 >> [] apic_timer_interrupt+0x1f/0x24 >> [] kvm_flush_remote_tlbs+0xce/0xdb [kvm] >> [] kvm_mmu_pte_write+0x1f2/0x368 [kvm] >> [] emulator_write_emulated_onepage+0x73/0xe6 [kvm] >> [] x86_emulate_insn+0x20d8/0x3348 [kvm] >> [] x86_decode_insn+0x624/0x872 [kvm] >> [] emulate_instruction+0x12b/0x258 [kvm] >> [] handle_exception+0x163/0x23f [kvm_intel] >> [] kvm_handle_exit+0x70/0x8a [kvm_intel] >> [] kvm_vcpu_ioctl_run+0x234/0x339 [kvm] >> [] kvm_vcpu_ioctl+0x0/0xa8f [kvm] >> [] kvm_vcpu_ioctl+0xbd/0xa8f [kvm] >> [] save_i387+0x23f/0x273 >> [] __next_cpu+0x12/0x21 >> [] find_busiest_group+0x177/0x462 >> [] setup_sigcontext+0x10d/0x190 >> [] get_page_from_freelist+0x96/0x310 >> [] get_page_from_freelist+0x2a6/0x310 >> [] flush_tlb_others+0x83/0xb3 >> [] flush_tlb_page+0x74/0x77 >> [] set_page_dirty_balance+0x8/0x35 >> [] do_wp_page+0x3a5/0x3bd >> [] dequeue_signal+0x2d/0x9c >> [] __handle_mm_fault+0x81b/0x87b >> [] kvm_vcpu_ioctl+0x0/0xa8f [kvm] >> [] do_ioctl+0x1c/0x5d >> [] vfs_ioctl+0x24a/0x25c >> [] sys_ioctl+0x48/0x5f >> [] syscall_call+0x7/0xb >> >> >> I am working with kvm-48, but also tried the 20071020 snapshot. The >> stuck code is kvm_flush_remote_tlbs(): >> >> while (atomic_read(&completed) !=3D needed) { >> cpu_relax(); >> barrier(); >> } >> > = > This part has been removed by commit > 49d3bd7e2b990e717aa66e229410b8f5096c4956, perhaps you could try it ? > = > commit 49d3bd7e2b990e717aa66e229410b8f5096c4956 > Author: Laurent Vivier > Date: Mon Oct 22 16:33:07 2007 +0200 > = > KVM: Use new smp_call_function_mask() in kvm_flush_remote_tlbs() > = > In kvm_flush_remote_tlbs(), replace a loop using > smp_call_function_single() > by a single call to smp_call_function_mask() (which is new for x86_64= ). > = > Signed-off-by: Laurent Vivier > Signed-off-by: Avi Kivity > = >> which I take to mean one of the CPUs is not ack'ing the TLB flush >> request. = > = > Yes, it seems... > = >> Is this is a known bug and any options to correct it? It works fine >> with 2 vcpus, but for a comparison with xen I'd like to get the vm >> working with 4. >> >> >> Host stats: >> OS: RHEL5 >> Processors: 2-Core 2 Duos (4 processors) >> KVM: kvm-48 and kvm-20071020-1 snapshot rpms >> QEMU command: >> >> qemu-kvm -boot c -localtime -hda /opt/kvm/images/cucm.img -m 1536 -smp >> 4 -serial file:/tmp/serial.log -net >> nic,macaddr=3D00:1a:4b:34:74:52,model=3Drtl8139 -net >> tap,ifname=3Dtap0,script=3D/bin/true -vnc :2 -monitor stdio >> >> >> thanks, >> >> david >> >> ------------------------------------------------------------------------- >> This SF.net email is sponsored by: Splunk Inc. >> Still grepping through log files to find problems? Stop. >> Now Search log events and configuration files using AJAX and a browser. >> Download your FREE copy of Splunk now >> http://get.splunk.com/ >> _______________________________________________ >> kvm-devel mailing list >> kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org >> https://lists.sourceforge.net/lists/listinfo/kvm-devel >> > = > = ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/