From 920552b213e3dc832a874b4e7ba29ecddbab31bc Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 18 Sep 2015 12:34:53 +0200 Subject: 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 Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'virt') 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. */ -- cgit v1.2.3