Messages in this thread | | | Date | Thu, 10 Oct 2013 10:43:43 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] kvm fix: Enable pvspinlock after jump_label_init() to avoid VM hang |
| |
On Wed, 9 Oct 2013 14:33:21 +0530 Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> wrote:
> We use jump label to enable pv-spinlock. With the changes in > (442e0973e927 Merge branch 'x86/jumplabel'), the jump label behaviour has changed > that would result in evntual hang of the VM since we would end up in a situation > where slowpath locks would halt the vcpus but we will not be able to wakeup the > vcpu by lock releaser using unlock kick. > > Similar problem in Xen and more detailed description is available in > a945928ea270 (xen: Do not enable spinlocks before jump_label_init() has executed) > > This patch splits kvm_spinlock_init to separate jump label changes with pvops > patching and also make jump label enabling after jump_label_init(). > > Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
-- Steve
> --- > Thanks to Andrew Theurer who reported weird behaviour of pvspinlock > in 3.12-rc that led to my git bisection and investigation and Konrad > for his jump label findings for Xen. > > arch/x86/kernel/kvm.c | 17 ++++++++++++++--- > 1 file changed, 14 insertions(+), 3 deletions(-) >
| |