|
From: | Peter Lieven |
Subject: | Re: [Qemu-devel] slow virtio network with vhost=on and multiple cores |
Date: | Tue, 13 Nov 2012 12:44:02 +0100 |
User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121028 Thunderbird/16.0.2 |
On 09.11.2012 19:03, Peter Lieven wrote:
Remark: If i disable interrupts on CPU1-3 for virtio the performance is ok again. Now we need someone with deeper knowledge of the in-kernel irqchip and the virtio/vhost driver development to say if this is a regression in qemu-kvm or a problem with the old virtio drivers if they receive the interrupt on different CPUs.
anyone?
Peter Lieven wrote:it seems that with in-kernel irqchip the interrupts are distributed across all vpcus. without in-kernel irqchip all interrupts are on cpu0. maybe this is related. without inkernel irqchip CPU0 CPU1 CPU2 CPU3 0: 16 0 0 0 IO-APIC-edge timer 1: 23 0 0 0 IO-APIC-edge i8042 4: 1 0 0 0 IO-APIC-edge 6: 4 0 0 0 IO-APIC-edge floppy 7: 0 0 0 0 IO-APIC-edge parport0 8: 0 0 0 0 IO-APIC-edge rtc0 9: 0 0 0 0 IO-APIC-fasteoi acpi 11: 76 0 0 0 IO-APIC-fasteoi uhci_hcd:usb1 12: 102 0 0 0 IO-APIC-edge i8042 14: 0 0 0 0 IO-APIC-edge ata_piix 15: 16881 0 0 0 IO-APIC-edge ata_piix 24: 0 0 0 0 PCI-MSI-edge virtio1-config 25: 5225 0 0 0 PCI-MSI-edge virtio1-requests 26: 0 0 0 0 PCI-MSI-edge virtio0-config 27: 72493 0 0 0 PCI-MSI-edge virtio0-input ... with inkernel irqchip CPU0 CPU1 CPU2 CPU3 0: 16 0 0 0 IO-APIC-edge timer 1: 0 3 3 1 IO-APIC-edge i8042 4: 0 0 1 0 IO-APIC-edge 6: 1 0 1 2 IO-APIC-edge floppy 7: 0 0 0 0 IO-APIC-edge parport0 8: 0 0 0 0 IO-APIC-edge rtc0 9: 0 0 0 0 IO-APIC-fasteoi acpi 11: 7 9 4 1 IO-APIC-fasteoi uhci_hcd:usb1 12: 30 27 29 34 IO-APIC-edge i8042 14: 0 0 0 0 IO-APIC-edge ata_piix 15: 943 937 950 943 IO-APIC-edge ata_piix 24: 0 0 0 0 PCI-MSI-edge virtio0-config 25: 930 978 980 947 PCI-MSI-edge virtio0-input 26: 0 0 1 0 PCI-MSI-edge virtio0-output 27: 0 0 0 0 PCI-MSI-edge virtio1-config 28: 543 541 542 553 PCI-MSI-edge virtio1-requests ...
[Prev in Thread] | Current Thread | [Next in Thread] |