diff options
| author | David Hildenbrand <dahi@linux.vnet.ibm.com> | 2015-09-18 12:34:53 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-09-25 10:31:30 +0200 |
| commit | 920552b213e3dc832a874b4e7ba29ecddbab31bc (patch) | |
| tree | c07ed91961b7842a5056f98794c4827a0e493cea /virt | |
| parent | 58c95070da3a504fbeca7939435bbb062cb96ea3 (diff) | |
| download | lwn-920552b213e3dc832a874b4e7ba29ecddbab31bc.tar.gz lwn-920552b213e3dc832a874b4e7ba29ecddbab31bc.zip | |
KVM: disable halt_poll_ns as default for s390x
We observed some performance degradation on s390x with dynamic
halt polling. Until we can provide a proper fix, let's enable
halt_poll_ns as default only for supported architectures.
Architectures are now free to set their own halt_poll_ns
default value.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 04146a2e1d81..8db1d9361993 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -66,8 +66,8 @@ MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); -/* halt polling only reduces halt latency by 5-7 us, 500us is enough */ -static unsigned int halt_poll_ns = 500000; +/* Architectures should define their poll value according to the halt latency */ +static unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT; module_param(halt_poll_ns, uint, S_IRUGO | S_IWUSR); /* Default doubles per-vcpu halt_poll_ns. */ |