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| author | Bogdan Purcareata <bogdan.purcareata@freescale.com> | 2015-05-18 13:13:54 (GMT) |
|---|---|---|
| committer | Honghua Yin <Hong-Hua.Yin@freescale.com> | 2015-05-19 01:53:20 (GMT) |
| commit | ea9b03c57eec92f184b7d24a5086e1f335866c29 (patch) | |
| tree | 0570f7fd0df5eedd5ca7bded078810e255109d82 /arch | |
| parent | 4660e029b87eee5b2a28ee3ee13f2042548803fa (diff) | |
| download | linux-fsl-qoriq-ea9b03c57eec92f184b7d24a5086e1f335866c29.tar.xz | |
powerpc/kvm: Disable in-kernel MPIC emulation for PREEMPT_RT_FULL
Current in-kernel MPIC emulation for PowerPC is unsuitable for RT. More
specifically, the MPIC lock becomes a sleeping mutex, causing concurrency issues
on a KVM guest enter. Converting the lock to a raw_spinlock is still not a
viable solution, since the current implementation is prone to induce large
latencies with preemption and irqs disabled on the host kernel.
Patch aready applied in the upstream 3.18.13 RT patch, version 9 [1].
[1] http://www.spinics.net/lists/linux-rt-users/msg13340.html
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
Change-Id: Ie942de00717527ea78c2471f6a5153489f432e89
Reviewed-on: http://git.am.freescale.net:8181/36530
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Scott Wood <scottwood@freescale.com>
Reviewed-by: Honghua Yin <Hong-Hua.Yin@freescale.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kvm/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig index ffaef2c..78c3c30 100644 --- a/arch/powerpc/kvm/Kconfig +++ b/arch/powerpc/kvm/Kconfig @@ -155,6 +155,7 @@ config KVM_E500MC config KVM_MPIC bool "KVM in-kernel MPIC emulation" depends on KVM && E500 + depends on !PREEMPT_RT_FULL select HAVE_KVM_IRQCHIP select HAVE_KVM_IRQ_ROUTING select HAVE_KVM_MSI |