openstack
/
nova
Code Issues Proposed changes

Use no_timer_check with soft-qemu 

The Linux kernel timer check not working properly
when the hypervisor's thread preempted by the host CPU scheduler.

The timer check is automatically disabled with other types
of hypervisors including the hardware accelerated kvm,
but timer_check is not disabled when qemu used without hardware acceleration.

This issue is frequently mischaracterized as an SSH connectivity issue and
causes rechecks and occasional boot failures.

This change adds no_timer_check kernel parameter when we are using
uec images with qemu.

Closes-Bug: #1312199
Change-Id: I3cfdfe9048fe219fc12cdac8a399b496f237e55e
(cherry picked from commit 6b86a61fee)
This commit is contained in:
Attila Fazekas 2014-05-28 09:19:29 +02:00
parent 4c6b0f71c2
commit 485f25df18
2 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
nova/tests/virt/libvirt/test_libvirt.py
View File

@ -3548,6 +3548,10 @@ class LibvirtConnTestCase(test.TestCase):
check = (lambda t: t.find('./os/kernel'), None)
check_list.append(check)
if expect_kernel:
check = (lambda t: "no_timer_check" in t.find('./os/cmdline').
text, hypervisor_type == "qemu")
check_list.append(check)
# Hypervisors that only support vm_mode.HVM and Xen
# should not produce configuration that results in kernel
# arguments

4
nova/virt/libvirt/driver.py
View File

@ -3183,6 +3183,8 @@ class LibvirtDriver(driver.ComputeDriver):
else:
guest.os_cmdline = ("root=%s %s" % (root_device_name,
CONSOLE))
if CONF.libvirt.virt_type == "qemu":
guest.os_cmdline += " no_timer_check"
if rescue.get('ramdisk_id'):
guest.os_initrd = os.path.join(inst_path, "ramdisk.rescue")
@ -3193,6 +3195,8 @@ class LibvirtDriver(driver.ComputeDriver):
else:
guest.os_cmdline = ("root=%s %s" % (root_device_name,
CONSOLE))
if CONF.libvirt.virt_type == "qemu":
guest.os_cmdline += " no_timer_check"
if instance['ramdisk_id']:
guest.os_initrd = os.path.join(inst_path, "ramdisk")
else: