Re: [pve-devel] qemu kvm_steal_time bug
>>is this a guest kernel bug, or a qemu bug? qemu bug, definitively. Before kernel 3.16, the kvm_steal_time counter was freezing and since kernel 3.16, it's like it's at 100% usage. in both case, the value is wrong. That's occur with live migration, qemu save old value but restoring value is wrong is some case. (Details are in bug report) This counter is really just a monitoring counter, to see if host is overloaded and "steal" cpu time to guest. Until it's fixed, it's 100% safe to disable it. - Mail original - De: "dietmar" <diet...@proxmox.com> À: "aderumier" <aderum...@odiso.com>, "Stefan Priebe" <s.pri...@profihost.ag> Cc: "pve-devel" <pve-devel@pve.proxmox.com> Envoyé: Lundi 21 Septembre 2015 06:33:34 Objet: Re: [pve-devel] qemu kvm_steal_time bug is this a guest kernel bug, or a qemu bug? On 09/17/2015 04:41 PM, Alexandre DERUMIER wrote: > Some news info about this bug: > > https://bugs.launchpad.net/qemu/+bug/1494350?comments=all > > > I have hited the bug again. > (No production impact, but my monitoring probes become crazy because of cpu > steal at 100%) > > I don't know if we could setup -kvm_steal_time by default for now ? > (it'll not break migration) > > or maybe add cpuflags options to vmid.conf ? > > ___ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
Re: [pve-devel] qemu kvm_steal_time bug
is this a guest kernel bug, or a qemu bug? On 09/17/2015 04:41 PM, Alexandre DERUMIER wrote: Some news info about this bug: https://bugs.launchpad.net/qemu/+bug/1494350?comments=all I have hited the bug again. (No production impact, but my monitoring probes become crazy because of cpu steal at 100%) I don't know if we could setup -kvm_steal_time by default for now ? (it'll not break migration) or maybe add cpuflags options to vmid.conf ? ___ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
Re: [pve-devel] qemu kvm_steal_time bug
Some news info about this bug: https://bugs.launchpad.net/qemu/+bug/1494350?comments=all I have hited the bug again. (No production impact, but my monitoring probes become crazy because of cpu steal at 100%) I don't know if we could setup -kvm_steal_time by default for now ? (it'll not break migration) or maybe add cpuflags options to vmid.conf ? - Mail original - De: "aderumier" <aderum...@odiso.com> À: "Stefan Priebe" <s.pri...@profihost.ag> Cc: "pve-devel" <pve-devel@pve.proxmox.com> Envoyé: Vendredi 28 Août 2015 20:09:18 Objet: Re: [pve-devel] qemu kvm_steal_time bug >>Is it only with 3.16 kernel? Haven't seen this yet. Yes, I have reproduce it on 3 debian jessie kernel 3.16. But other jessie migration have worked before... I have asked to the qemu mailing, waiting for more information. - Mail original - De: "Stefan Priebe" <s.pri...@profihost.ag> À: "aderumier" <aderum...@odiso.com> Cc: "pve-devel" <pve-devel@pve.proxmox.com> Envoyé: Vendredi 28 Août 2015 17:07:07 Objet: Re: [pve-devel] qemu kvm_steal_time bug Is it only with 3.16 kernel? Haven't seen this yet. Stefan Excuse my typo s ent from my mobile phone. Am 28.08.2015 um 16:31 schrieb Alexandre DERUMIER < aderum...@odiso.com >: Hi, I have add this bug, which occur after live migration: https://code.google.com/p/ganeti/issues/detail?id=986 https://groups.google.com/forum/#!topic/ganeti/D2Yos3BShmc https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=785557#64 qemu 2.4 or 2.1 and guest kernel 3.16 (debian jessie). The bug is that after a live migration, the steal cpu counter just freeze at 100% # mpstat Linux 3.16.0-4-amd64 (radinsapi1) 28/08/2015 _x86_64_ (8 CPU) 16:24:51 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 16:24:51 all 0,00 0,00 0,00 0,00 0,00 0,00 99,92 0,00 0,00 0,08 Seem to be a qemu bug, the workaround seem to use -kvm_steal_time cpu flag. But I don't known if they are an performance impact or not. Does somebody already have had this bug ? Alexandre ___ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel ___ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel ___ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
[pve-devel] qemu kvm_steal_time bug
Hi, I have add this bug, which occur after live migration: https://code.google.com/p/ganeti/issues/detail?id=986 https://groups.google.com/forum/#!topic/ganeti/D2Yos3BShmc https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=785557#64 qemu 2.4 or 2.1 and guest kernel 3.16 (debian jessie). The bug is that after a live migration, the steal cpu counter just freeze at 100% # mpstat Linux 3.16.0-4-amd64 (radinsapi1) 28/08/2015 _x86_64_(8 CPU) 16:24:51 CPU%usr %nice%sys %iowait%irq %soft %steal %guest %gnice %idle 16:24:51 all0,000,000,000,000,000,00 99,92 0,000,000,08 Seem to be a qemu bug, the workaround seem to use -kvm_steal_time cpu flag. But I don't known if they are an performance impact or not. Does somebody already have had this bug ? Alexandre ___ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
Re: [pve-devel] qemu kvm_steal_time bug
Is it only with 3.16 kernel? Haven't seen this yet. Yes, I have reproduce it on 3 debian jessie kernel 3.16. But other jessie migration have worked before... I have asked to the qemu mailing, waiting for more information. - Mail original - De: Stefan Priebe s.pri...@profihost.ag À: aderumier aderum...@odiso.com Cc: pve-devel pve-devel@pve.proxmox.com Envoyé: Vendredi 28 Août 2015 17:07:07 Objet: Re: [pve-devel] qemu kvm_steal_time bug Is it only with 3.16 kernel? Haven't seen this yet. Stefan Excuse my typo s ent from my mobile phone. Am 28.08.2015 um 16:31 schrieb Alexandre DERUMIER aderum...@odiso.com : Hi, I have add this bug, which occur after live migration: https://code.google.com/p/ganeti/issues/detail?id=986 https://groups.google.com/forum/#!topic/ganeti/D2Yos3BShmc https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=785557#64 qemu 2.4 or 2.1 and guest kernel 3.16 (debian jessie). The bug is that after a live migration, the steal cpu counter just freeze at 100% # mpstat Linux 3.16.0-4-amd64 (radinsapi1) 28/08/2015 _x86_64_ (8 CPU) 16:24:51 CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 16:24:51 all 0,00 0,00 0,00 0,00 0,00 0,00 99,92 0,00 0,00 0,08 Seem to be a qemu bug, the workaround seem to use -kvm_steal_time cpu flag. But I don't known if they are an performance impact or not. Does somebody already have had this bug ? Alexandre ___ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel ___ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
