Public bug reported: Since the pc-bios update of qemu commit d7a51dbbaa70677846453f8c961590913052dd86, booting a NetBSD/i386 guest takes a very long time, apparently due to interrupt load.
For example, booting the NetBSD/i386 6.0 serial console install CD with wget ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-6.0/i386/installation/cdrom/boot-com.iso qemu-system-i386 -nographic -cdrom boot-com.iso used to take less than a minute, but now takes more like ten minutes to enter the "sysinst" installer; it's so slow that at first I thought it had hung. If I then exit the installer and type "vmstat -i", it shows a high interrupt rate on ioapic0 pin 9: # vmstat -i interrupt total rate cpu0 timer 336942 102 ioapic0 pin 9 256791232 78052 ioapic0 pin 1 1 0 ioapic0 pin 15 345 0 ioapic0 pin 4 102 0 ioapic0 pin 6 1 0 Total 257128623 78154 According to dmesg, this is the piixpm0 device: # dmesg [...] piixpm0 at pci0 dev 1 function 3: vendor 0x8086 product 0x7113 (rev. 0x03) timecounter: Timecounter "piixpm0" frequency 3579545 Hz quality 1000 piixpm0: 24-bit timer piixpm0: interrupting at ioapic0 pin 9 [...] Versions of qemu lacking commit d7a51dbbaa70677846453f8c961590913052dd86 do not have this problem. ** Affects: qemu Importance: Undecided Status: New -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1091241 Title: NetBSD/i386 6.0 guest suffers interrupt storm since qemu BIOS update Status in QEMU: New Bug description: Since the pc-bios update of qemu commit d7a51dbbaa70677846453f8c961590913052dd86, booting a NetBSD/i386 guest takes a very long time, apparently due to interrupt load. For example, booting the NetBSD/i386 6.0 serial console install CD with wget ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-6.0/i386/installation/cdrom/boot-com.iso qemu-system-i386 -nographic -cdrom boot-com.iso used to take less than a minute, but now takes more like ten minutes to enter the "sysinst" installer; it's so slow that at first I thought it had hung. If I then exit the installer and type "vmstat -i", it shows a high interrupt rate on ioapic0 pin 9: # vmstat -i interrupt total rate cpu0 timer 336942 102 ioapic0 pin 9 256791232 78052 ioapic0 pin 1 1 0 ioapic0 pin 15 345 0 ioapic0 pin 4 102 0 ioapic0 pin 6 1 0 Total 257128623 78154 According to dmesg, this is the piixpm0 device: # dmesg [...] piixpm0 at pci0 dev 1 function 3: vendor 0x8086 product 0x7113 (rev. 0x03) timecounter: Timecounter "piixpm0" frequency 3579545 Hz quality 1000 piixpm0: 24-bit timer piixpm0: interrupting at ioapic0 pin 9 [...] Versions of qemu lacking commit d7a51dbbaa70677846453f8c961590913052dd86 do not have this problem. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1091241/+subscriptions
