----- Original Message ----- > From: "Stefan Priebe" <s.pri...@profihost.ag> > To: "Paolo Bonzini" <pbonz...@redhat.com>, "qemu-devel" > <qemu-devel@nongnu.org>, k...@vger.kernel.org > Sent: Monday, February 22, 2016 8:35:41 PM > Subject: Re: kernel 4.4.2: kvm_irq_delivery_to_api / rwsem_down_read_failed > > > Am 22.02.2016 um 18:36 schrieb Paolo Bonzini: > > > > > > On 20/02/2016 11:44, Stefan Priebe wrote: > >> Hi, > >> > >> while testing Kernel 4.4.2 and starting 20 Qemu 2.4.1 virtual machines. > >> I got those traces and a load of 500 on those system. I was only abler > >> to recover by sysrq-trigger. > > > > It seems like something happening at the VM level. A task took the mm > > semaphore and hung everyone else. Difficult to debug without a core > > (and without knowing who held the semaphore). Sorry. > > OK thank you anyway. Is there anything i can do if this happens again?
Try grabbing a vmcore with sysrq-c, if you have kdump configured. Paolo
