From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: qemu polling KVM_IRQ_LINE_STATUS when stopped Date: Wed, 18 Oct 2017 10:49:46 -0700 Message-ID: <20171018174946.GU5109@tassilo.jf.intel.com> References: <87a80pihlz.fsf@linux.intel.com> <1ffc9cf7-a81c-6eeb-4823-c6e0ef53d3af@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: kvm@vger.kernel.org To: Paolo Bonzini Return-path: Received: from mga02.intel.com ([134.134.136.20]:23004 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751129AbdJRRts (ORCPT ); Wed, 18 Oct 2017 13:49:48 -0400 Content-Disposition: inline In-Reply-To: <1ffc9cf7-a81c-6eeb-4823-c6e0ef53d3af@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: > Because the polling time is zero here, and fd=7 has POLLIN, it seems > that QEMU is continuously scheduling a callback (a timer with a deadline > in the past, or a bottom half). Can you perhaps attach gdb and see what > callback it is? There seem to be multiple. The ioctl appears to be the PIC timer - 6.36% __GI___ioctl ▒ kvm_vm_ioctl ▒ kvm_set_irq ▒ kvm_pic_set_irq It does something with glib (windows are all closed BTW) - 2.83% libglib-2.0.so.0.5200.3 [.] g_main_context_check ▒ - 2.81% g_main_context_check ▒ - 2.60% main_loop_wait ▒ main ▒ __libc_start_main ▒ _start And some AIO is going on, not sure what triggers that. 1.96% aio_ctx_check ▒ -Andi